-
question_answer1)
One kilowatt hour is equal to [NCERT 1974; MP PMT 2002]
A)
\[36\times {{10}^{5}}\,joules\] done
clear
B)
\[36\times {{10}^{3}}\,joules\] done
clear
C)
\[{{10}^{3}}\,joules\] done
clear
D)
\[{{10}^{5}}\,joules\] done
clear
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question_answer2)
If \[{{R}_{1}}\] and \[{{R}_{2}}\] are respectively the filament resistances of a 200 watt bulb and 100 watt bulb designed to operate on the same voltage, then [NCERT 1980; CPMT 1991, 97]
A)
\[{{R}_{1}}\] is two times \[{{R}_{2}}\] done
clear
B)
\[{{R}_{2}}\] is two times \[{{R}_{1}}\] done
clear
C)
\[{{R}_{2}}\] is four times \[{{R}_{1}}\] done
clear
D)
\[{{R}_{1}}\] is four times \[{{R}_{2}}\] done
clear
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question_answer3)
Two electric bulbs, one of 200 volt 40 watt and the other 200 volt 100 watt are connected in a house wiring circuit [NCERT 1971; CBSE PMT 2000]
A)
They have equal currents through them done
clear
B)
The resistance of the filaments in both the bulbs is same done
clear
C)
The resistance of the filament in 40 watt bulb is more than the resistance in 100 watt bulb done
clear
D)
The resistance of the filament in 100 watt bulb is more than the resistance in 40 watt bulb done
clear
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question_answer4)
The two bulbs as in the above question are connected in series to a 200 volt line. Then [NCERT 1971, 78]
A)
The potential drop across the two bulbs is the same done
clear
B)
The potential drop across the 40 watt bulb is greater than the potential drop across the 100 watt bulb done
clear
C)
The potential drop across the 100 W bulb is greater than the potential drop across the 40 W bulb done
clear
D)
The potential drop across both the bulb is 200 volt done
clear
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question_answer5)
Forty electric bulbs are connected in series across a 220 V supply. After one bulb is fused, the remaining 39 are connected again in series across the same supply. The illumination will be [NCERT 1972; Haryana CEE 1996; DPMT 2001]
A)
More with 40 bulbs than with 39 done
clear
B)
More with 39 bulbs than with 40 done
clear
C)
Equal in both the cases done
clear
D)
In the ratio of \[{{49}^{2}}:{{39}^{2}}\] done
clear
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question_answer6)
The material of fuse wire should have [BHU 1999; MH CET 2001; CBSE PMT 2003]
A)
A high specific resistance and high melting point done
clear
B)
A low specific resistance and low melting point done
clear
C)
A high specific resistance and low melting point done
clear
D)
A low specific resistance and a high melting point done
clear
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question_answer7)
Two electric bulbs whose resistances are in the ratio of 1 : 2 are connected in parallel to a constant voltage source. The powers dissipated in them have the ratio [NCERT 1977; MP PMT 1994, 2000]
A)
1 : 2 done
clear
B)
1 : 1 done
clear
C)
2 : 1 done
clear
D)
1 : 4 done
clear
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question_answer8)
A heater coil is cut into two parts of equal length and one of them is used in the heater. The ratio of the heat produced by this half coil to that by the original coil is [NCERT 1972; AIEEE 2005; CBSE PMT 2005]
A)
2 : 1 done
clear
B)
1 : 2 done
clear
C)
1 : 4 done
clear
D)
4 : 1 done
clear
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question_answer9)
Resistance of one carbon filament and one tungsten lamp are measured individually when the lamp are lit and compared with their respective resistances when cold. Which one of the following statements will be true [NCERT 972]
A)
Resistance of the carbon filament lamp will increase but that of the tungsten will diminish when hot done
clear
B)
Resistance of the tungsten filament lamp will increase but that of carbon will diminish when hot done
clear
C)
Resistances of both the lamps will increase when hot done
clear
D)
Resistances of both the lamps will decrease when hot done
clear
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question_answer10)
The mechanism of the heat produced in a conductor when an electric current flows through it, can be explained on the basis of
A)
Viscosity done
clear
B)
Friction done
clear
C)
Free electron theory done
clear
D)
Gauss's theorem done
clear
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question_answer11)
Two electric bulbs whose resistances are in the ratio of 1 : 2 are connected in series. The powers dissipated in them have the ratio [NCERT 1977]
A)
1 : 2 done
clear
B)
2 : 1 done
clear
C)
1 : 1 done
clear
D)
1 : 4 done
clear
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question_answer12)
You are given a resistance wire of length 50 cm and a battery of negligible resistance. In which of the following cases is largest amount of heat generated
A)
When the wire is connected to the battery directly done
clear
B)
When the wire is divided into two parts and both the parts connected to the battery in parallel done
clear
C)
When the wire is divided into four parts and all the four connected to the battery in parallel done
clear
D)
When only half the wire is connected to the battery done
clear
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question_answer13)
What is immaterial for an electric fuse wire [MNR 1984; MP PMT 2002; CPMT 1996, 2003]
A)
Its specific resistance done
clear
B)
Its radius done
clear
C)
Its length done
clear
D)
Current flowing through it done
clear
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question_answer14)
The electric bulbs have tungsten filaments of same length. If one of them gives 60 watt and other 100 watt, then [NCERT 1979]
A)
100 watt bulb has thicker filament done
clear
B)
60 watt bulb has thicker filament done
clear
C)
Both filaments are of same thickness done
clear
D)
It is possible to get different wattage unless the lengths are different done
clear
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question_answer15)
Three equal resistors connected in series across a source of e.m.f. together dissipate 10 watt. If the same resistors are connected in parallel across the same e.m.f., then the power dissipated will be [CBSE PMT 1998; KCET (Engg.) 1999; MP PMT 2003]
A)
10 watt done
clear
B)
30 watt done
clear
C)
10/3 watt done
clear
D)
90 watt done
clear
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question_answer16)
How much energy in kilowatt hour is consumed in operating ten 50 watt bulbs for 10 hours per day in a month (30 days). [NCERT 1978, 80; CPMT 1991]
A)
1500 done
clear
B)
5,000 done
clear
C)
15 done
clear
D)
150 done
clear
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question_answer17)
(1) The product of a volt and a coulomb is a joule. (2) The product of a volt and an ampere is a joule/second. (3) The product of volt and watt is horse power. (4) Watt-hour can be measured in terms of electron volt. State if [NCERT 1978; MP PMT 2003]
A)
All four are correct done
clear
B)
(1), (2) and (4) are correct done
clear
C)
(1) and (3) are correct done
clear
D)
(3) and (4) are correct done
clear
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question_answer18)
A 25 W, 220 V bulb and a 100 W, 220 V bulb are connected in parallel across a 440 V line [CBSE PMT 2001]
A)
Only 100 watt bulb will fuse done
clear
B)
Only 25 watt bulb will fuse done
clear
C)
Both bulbs will fuse done
clear
D)
None of the bulbs will fuse done
clear
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question_answer19)
Two electric lamps of 40 watt each are connected in parallel. The power consumed by the combination will be [CPMT 1984]
A)
20 watt done
clear
B)
60 watt done
clear
C)
80 watt done
clear
D)
100 watt done
clear
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question_answer20)
Two heating coils, one of fine wire and the other of thick wire of the same material and of the same length are connected in series and in parallel. Which of the following statement is correct
A)
In series fine wire liberates more energy while in parallel thick wire will liberate more energy done
clear
B)
In series fine wire liberates less energy while in parallel thick wire will liberate more energy done
clear
C)
Both will liberate equally done
clear
D)
In series the thick wire will liberate more while in parallel it will liberate less energy done
clear
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question_answer21)
An electric bulb is rated 220 volt and 100 watt. Power consumed by it when operated on 110 volt is [CPMT 1986; MP PMT 1986, 94; AFMC 2000]
A)
50 watt done
clear
B)
75 watt done
clear
C)
90 watt done
clear
D)
25 watt done
clear
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question_answer22)
A 25 watt, 220 volt bulb and a 100 watt, 220 volt bulb are connected in series across a 220 volt lines. Which electric bulb will glow more brightly [MP PET 1999; MP PMT 1999]
A)
25 watt bulb done
clear
B)
100 watt bulb done
clear
C)
First 25 watt and then 100 watt done
clear
D)
Both with same brightness done
clear
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question_answer23)
A resistor \[{{R}_{1}}\] dissipates the power P when connected to a certain generator. If the resistor \[{{R}_{2}}\] is put in series with \[{{R}_{1}}\], the power dissipated by \[{{R}_{1}}\] [CPMT 1985; MNR 1998]
A)
Decreases done
clear
B)
Increases done
clear
C)
Remains the same done
clear
D)
Any of the above depending upon the relative values of \[{{R}_{1}}\] and \[{{R}_{2}}\] done
clear
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question_answer24)
An electric fan and a heater are marked as 100 watt, 220 volt and 1000 watt, 220 volt respectively. The resistance of the heater is [CPMT 1990]
A)
Zero done
clear
B)
Greater than that of the fan done
clear
C)
Less than that of the fan done
clear
D)
Equal to that of the fan done
clear
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question_answer25)
According to Joule's law, if the potential difference across a conductor having a material of specific resistance remains constant, then the heat produced in the conductor is directly proportional to [MP PMT 1986]
A)
\[\rho \] done
clear
B)
\[{{\rho }^{2}}\] done
clear
C)
\[\frac{1}{\sqrt{\rho }}\] done
clear
D)
\[\frac{1}{\rho }\] done
clear
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question_answer26)
Two heater wires of equal length are first connected in series and then in parallel. The ratio of heat produced in the two cases is [MNR 1987; UPSEAT 1999; MP PMT 1996, 2000, 01; AIIMS 2000; MP PET 1999, 2002; BHU 2004; Pb PET 2004]
A)
2 : 1 done
clear
B)
1 : 2 done
clear
C)
4 : 1 done
clear
D)
1 : 4 done
clear
View Solution play_arrow
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question_answer27)
Two bulbs of equal wattage, one having carbon filament and the other having a tungsten filament are connected in series to the mains, then
A)
Both bulbs glow equally done
clear
B)
Carbon filament bulb glows more done
clear
C)
Tungsten filament bulbs glows more done
clear
D)
Carbon filament bulb glows less done
clear
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question_answer28)
Two identical heaters rated 220 volt, 1000 watt are placed in series with each other across 220 volt lines. If resistance do not change with temperature, then the combined power is
A)
1000 watt done
clear
B)
2000 watt done
clear
C)
500 watt done
clear
D)
4000 watt done
clear
View Solution play_arrow
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question_answer29)
A 25 watt, 220 volt bulb and a 100 watt, 220 volt bulb are connected in parallel across a 220 volt line. Which bulb will glow more brightly
A)
25 watt bulb done
clear
B)
100 watt bulb done
clear
C)
Both will have same brightness done
clear
D)
First 25 watt then 100 watt done
clear
View Solution play_arrow
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question_answer30)
If two bulbs of wattage 25 and 100 respectively each rated at 220 volt are connected in series with the supply of 440 volt, then which bulbs will fuse [MNR 1988]
A)
100 watt bulb done
clear
B)
25 watt bulb done
clear
C)
None of them done
clear
D)
Both of them done
clear
View Solution play_arrow
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question_answer31)
If current in an electric bulb changes by 1%, then the power will change by [AFMC 1996]
A)
1% done
clear
B)
2% done
clear
C)
4% done
clear
D)
\[\frac{1}{2}%\] done
clear
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question_answer32)
Two identical batteries, each of e.m.f. 2 volt and internal resistance 1.0 ohm are available to produce heat in an external resistance \[R=0.5\]ohm by passing a current through it. The maximum Joulean power that can be developed across R using these batteries is [CBSE PMT 1990; BHU 1997]
A)
1.28 watt done
clear
B)
2.0 watt done
clear
C)
\[\frac{8}{9}\,watt\] done
clear
D)
3.2 watt done
clear
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question_answer33)
A constant voltage is applied between the two ends of a metallic wire. If both the length and the radius of the wire are doubled, the rate of heat developed in the wire [MP PMT 1996]
A)
Will be doubled done
clear
B)
Will be halved done
clear
C)
Will remain the same done
clear
D)
Will be quadrupled done
clear
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question_answer34)
The heating coils rating at 220 volt and producing 50 cal/sec heat are available with the resistances \[55\,\Omega ,\ 110\,\Omega ,\ 220\,\Omega \] and \[440\,\Omega \]. The heater of maximum power will be of [MP PMT 1985]
A)
\[440\,\Omega \] done
clear
B)
\[220\,\Omega \] done
clear
C)
\[110\,\Omega \] done
clear
D)
\[55\,\Omega \] done
clear
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question_answer35)
Which of the following statement is false
A)
Heat produced in a conductor is proportional to its resistance done
clear
B)
Heat produced in a conductor is proportional to the square of the current done
clear
C)
Heat produced in a conductor is proportional to charge done
clear
D)
Heat produced in a conductor is proportional to the time for which current is passed done
clear
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question_answer36)
On an electric heater 220 volt and 1100 watt are marked. On using it for 4 hours, the energy consumed in kWh will be
A)
2 done
clear
B)
4.4 done
clear
C)
6 done
clear
D)
8 done
clear
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question_answer37)
An electric heater kept in vacuum is heated continuously by passing electric current. Its temperature [MP PET 1993]
A)
Will go on rising with time done
clear
B)
Will stop after sometime as it will loose heat to the surroundings by conduction done
clear
C)
Will rise for sometime and there after will start falling done
clear
D)
Will become constant after sometime because of loss of heat due to radiation done
clear
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question_answer38)
Heat produced in a wire of resistance R due to current flowing at constant potential difference is proportional to [MP PET 1993]
A)
\[\frac{1}{{{R}^{2}}}\] done
clear
B)
\[\frac{1}{R}\] done
clear
C)
R done
clear
D)
\[{{R}^{2}}\] done
clear
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question_answer39)
The power rating of an electric motor which draws a current of 3.75 amperes when operated at 200 V is about
A)
1 H.P. done
clear
B)
500 W done
clear
C)
54 W done
clear
D)
750 H.P. done
clear
View Solution play_arrow
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question_answer40)
An electric bulb of 100 watt is connected to a supply of electricity of 220 V. Resistance of the filament is [EAMCET 1981, 82; MP PMT 1993, 97]
A)
\[484\,\Omega \] done
clear
B)
\[100\,\Omega \] done
clear
C)
\[22000\,\Omega \] done
clear
D)
\[242\,\Omega \] done
clear
View Solution play_arrow
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question_answer41)
A cable of resistance \[10\,\Omega \] carries electric power from a generator producing 250 kW at 10000 volt. The current in the cable is
A)
25 A done
clear
B)
250 A done
clear
C)
100 A done
clear
D)
1000 A done
clear
View Solution play_arrow
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question_answer42)
In the above question, the power lost in the cable during transmission is
A)
12.5 kW done
clear
B)
6.25 kW done
clear
C)
25 kW done
clear
D)
3.15 kW done
clear
View Solution play_arrow
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question_answer43)
The heat generated through 2 ohm and 8 ohm resistances separately, when a condenser of 200\[\mu F\] capacity charged to 200 V is discharged one by one, will be [MP PET 1993]
A)
4 J and 16 J respectively done
clear
B)
16 J and 4 J respectively done
clear
C)
4 J and 8 J respectively done
clear
D)
4 J and 4 J respectively done
clear
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question_answer44)
Two bulbs are in parallel and they together consume 48 W from a battery of 6 V. The resistance of each bulb is
A)
\[0.67\,\Omega \] done
clear
B)
\[3.0\,\Omega \] done
clear
C)
\[4.0\,\Omega \] done
clear
D)
\[1.5\,\Omega \] done
clear
View Solution play_arrow
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question_answer45)
The heat developed in an electric wire of resistance R by a current I for a time t is [MP PMT 1993; MP PET 2005]
A)
\[\frac{{{I}^{2}}Rt}{4.2}cal\] done
clear
B)
\[\frac{{{I}^{2}}t}{4.2R}cal\] done
clear
C)
\[\frac{{{I}^{2}}R}{4.2\,t}cal\] done
clear
D)
\[\frac{Rt}{4.2\,{{I}^{2}}}cal\] done
clear
View Solution play_arrow
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question_answer46)
Two bulbs, one of 50 watt and another of 25 watt are connected in series to the mains. The ratio of the currents through them is [JIPMER 1997]
A)
2 : 1 done
clear
B)
1 : 2 done
clear
C)
1 : 1 done
clear
D)
Without voltage, cannot be calculated done
clear
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question_answer47)
The brightness of a bulb will be reduced, if a resistance is connected in
A)
Series with it done
clear
B)
Parallel with it done
clear
C)
Series or parallel with it done
clear
D)
Brightness of the bulb cannot be reduced done
clear
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question_answer48)
A 100 watt bulb working on 200 volt and a 200 watt bulb working on 100 volt have
A)
Resistances in the ratio of 4 : 1 done
clear
B)
Maximum current ratings in the ratio of \[1:4\] done
clear
C)
Resistances in the ratio of 2 : 1 done
clear
D)
Maximum current ratings in the ratio of 1 : 2 done
clear
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question_answer49)
There are two electric bulbs of 40 W and 100 W. Which one will be brighter when first connected in series and then in parallel, [MP PET 1993]
A)
40 W in series and 100 W in parallel done
clear
B)
100 W in series and 40 W in parallel done
clear
C)
40 W both in series and parallel will be uniform done
clear
D)
100 W both in series and parallel will be uniform done
clear
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question_answer50)
Two resistances \[{{R}_{1}}\] and \[{{R}_{2}}\] when connected in series and parallel with 120 V line, power consumed will be 25 W and 100 W respectively. Then the ratio of power consumed by \[{{R}_{1}}\] to that consumed by \[{{R}_{2}}\] will be [EAMCET 1983]
A)
1 : 1 done
clear
B)
1 : 2 done
clear
C)
2 : 1 done
clear
D)
1 : 4 done
clear
View Solution play_arrow
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question_answer51)
A 220 volt and 800 watt electric kettle and three 220 volt and 100 watt bulbs are connected in parallel. On connecting this combination with 220 volt electric supply, the total current will be [MP PMT 1975]
A)
0.15 ampere done
clear
B)
5.0 ampere done
clear
C)
5.5 ampere done
clear
D)
6.9 ampere done
clear
View Solution play_arrow
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question_answer52)
You are given three bulbs of 25, 40 and 60 watt. Which of them has lowest resistance [NCERT 1982]
A)
25 watt bulb done
clear
B)
40 watt bulb done
clear
C)
60 watt bulb done
clear
D)
Information is insufficient done
clear
View Solution play_arrow
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question_answer53)
The value of internal resistance of an ideal cell is [EAMCET 1989]
A)
Zero done
clear
B)
\[0.5\,\Omega \] done
clear
C)
\[1\,\Omega \] done
clear
D)
Infinity done
clear
View Solution play_arrow
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question_answer54)
Electric power is transmitted over long distances through conducting wires at high voltage because [MP PET 1994]
A)
High voltage travels faster done
clear
B)
Power loss is large done
clear
C)
Power loss is less done
clear
D)
Generator produced electrical energy at a very high voltage done
clear
View Solution play_arrow
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question_answer55)
A coil develops heat of 800 cal/sec. When 20 volts is applied across its ends. The resistance of the coil is (1 cal = 4.2 joule) [MP PET 1994]
A)
\[1.2\,\Omega \] done
clear
B)
\[1.4\,\Omega \] done
clear
C)
\[0.12\,\Omega \] done
clear
D)
\[0.14\,\Omega \] done
clear
View Solution play_arrow
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question_answer56)
Resistances \[{{R}_{1}}\] and \[{{R}_{2}}\] are joined in parallel and a current is passed so that the amount of heat liberated is \[{{H}_{1}}\] and \[{{H}_{2}}\] respectively. The ratio \[\frac{{{H}_{1}}}{{{H}_{2}}}\] has the value [MP PMT 1994]
A)
\[\frac{{{R}_{2}}}{{{R}_{1}}}\] done
clear
B)
\[\frac{{{R}_{1}}}{{{R}_{2}}}\] done
clear
C)
\[\frac{R_{1}^{2}}{R_{2}^{2}}\] done
clear
D)
\[\frac{R_{2}^{2}}{R_{1}^{2}}\] done
clear
View Solution play_arrow
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question_answer57)
The internal resistance of a primary cell is 4 ohm. It generates a current of 0.2 amp in an external resistance of 21 ohm. The rate at which chemical energy is consumed in providing the current is [MP PMT 1994]
A)
\[0.42\,J/s\] done
clear
B)
\[0.84\,J/s\] done
clear
C)
\[5\,J/s\] done
clear
D)
\[1\,J/s\] done
clear
View Solution play_arrow
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question_answer58)
A heating coil is labelled 100 W, 220 V. The coil is cut in half and the two pieces are joined in parallel to the same source. The energy now liberated per second is [CBSE PMT 1995]
A)
200 J done
clear
B)
400 J done
clear
C)
25 J done
clear
D)
50 J done
clear
View Solution play_arrow
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question_answer59)
Which of the following is not a correct statement [MP PET 1995]
A)
Resistivity of electrolytes decreases on increasing temperature done
clear
B)
Resistance of mercury falls on decreasing its temperature done
clear
C)
When joined in series a 40 W bulb glows more than a 60 W bulb done
clear
D)
Resistance of 40 W bulb is less than the resistance of 60 W bulb done
clear
View Solution play_arrow
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question_answer60)
Three light bulbs of 40 W, 60 W and 100 W are connected in series with 220 V source. Which one of the bulbs will glow brightest [MP PMT 1995; UPSEAT 2002; BCECE 2005]
A)
40 W done
clear
B)
60 W done
clear
C)
100 W done
clear
D)
All with the same brightness done
clear
View Solution play_arrow
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question_answer61)
The energy consumed in 1 kilowatt electric heater in 30 seconds will be
A)
\[6\times {{10}^{2}}\,J\] done
clear
B)
\[4.99\times {{10}^{7}}\,J\] done
clear
C)
\[9.8\times {{10}^{6}}\,J\] done
clear
D)
\[3\times {{10}^{4}}\,J\] done
clear
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question_answer62)
Two bulbs of 500 watt and 200 watt are manufactured to operate on 220 volt line. The ratio of heat produced in 500 W and 200 W, in two cases, when firstly they are joined in parallel and secondly in series, will be [MP PET 1996; DPMT 1999]
A)
\[\frac{5}{2},\,\frac{2}{5}\] done
clear
B)
\[\frac{5}{2},\,\frac{5}{2}\] done
clear
C)
\[\frac{2}{5},\,\frac{5}{2}\] done
clear
D)
\[\frac{2}{5},\,\frac{2}{5}\] done
clear
View Solution play_arrow
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question_answer63)
A 60 watt bulb carries a current of 0.5 amp. The total charge passing through it in 1 hour is [MP PMT 1996]
A)
3600 coulomb done
clear
B)
3000 coulomb done
clear
C)
2400 coulomb done
clear
D)
1800 coulomb done
clear
View Solution play_arrow
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question_answer64)
An electric heater of resistance 6 ohm is run for 10 minutes on a 120 volt line. The energy liberated in this period of time is [MP PMT 1996]
A)
\[7.2\times {{10}^{3}}\,J\] done
clear
B)
\[14.4\times {{10}^{5}}\,J\] done
clear
C)
\[43.2\times {{10}^{4}}\,J\] done
clear
D)
\[28.8\times {{10}^{4}}J\] done
clear
View Solution play_arrow
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question_answer65)
Two bulbs are working in parallel order. Bulb A is brighter than bulb B. If \[{{R}_{A}}\] and \[{{R}_{B}}\] are their resistance respectively then [MP PMT 2003]
A)
\[{{R}_{A}}>{{R}_{B}}\] done
clear
B)
\[{{R}_{A}}<{{R}_{B}}\] done
clear
C)
\[{{R}_{A}}={{R}_{B}}\] done
clear
D)
None of these done
clear
View Solution play_arrow
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question_answer66)
Two conductors made of the same material are connected across a common potential difference. Conductor A has twice the diameter and twice the length of conductor B. The power delivered to the two conductors \[{{P}_{A}}\] and \[{{P}_{B}}\] respectively is such that \[{{P}_{A}}/{{P}_{B}}\] equals to
A)
0.5 done
clear
B)
1.0 done
clear
C)
1.5 done
clear
D)
2.0 done
clear
View Solution play_arrow
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question_answer67)
A heating coil can heat the water of a vessel from \[20{}^\circ C\] to \[60{}^\circ C\] in 30 minutes. Two such heating coils are put in series and then used to heat the same amount of water through the same temperature range. The time taken now will be (neglecting thermal capacity of the coils) [MP PMT 1997]
A)
60 minutes done
clear
B)
30 minutes done
clear
C)
15 minutes done
clear
D)
7.5 minutes done
clear
View Solution play_arrow
-
question_answer68)
If 2.2 kilowatt power is transmitted through a 10 ohm line at 22000 volt, the power loss in the form of heat will be [MP PMT/PET 1998]
A)
0.1 watt done
clear
B)
1 watt done
clear
C)
10 watt done
clear
D)
100 watt done
clear
View Solution play_arrow
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question_answer69)
Two resistors having equal resistances are joined in series and a current is passed through the combination. Neglect any variation in resistance as the temperature changes. In a given time interval [MP PMT 1999]
A)
Equal amounts of thermal energy must be produced in the resistors done
clear
B)
Unequal amounts of thermal energy may be produced done
clear
C)
The temperature must rise equally in the resistors done
clear
D)
The temperature must rise unequally in the resistors done
clear
View Solution play_arrow
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question_answer70)
A \[5{}^\circ C\] rise in temperature is observed in a conductor by passing a current. When the current is doubled the rise in temperature will be approximately [CBSE PMT 1998]
A)
\[16{}^\circ C\] done
clear
B)
\[10{}^\circ C\] done
clear
C)
\[20{}^\circ C\] done
clear
D)
\[12{}^\circ C\] done
clear
View Solution play_arrow
-
question_answer71)
Watt-hour meter measures [KCET 1994]
A)
Electric energy done
clear
B)
Current done
clear
C)
Voltage done
clear
D)
Power done
clear
View Solution play_arrow
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question_answer72)
An electric lamp is marked 60 W, 230 V. The cost of 1 kilowatt hour of power is Rs. 1.25. The cost of using this lamp for 8 hours is [KCET 1994]
A)
Rs. 1.20 done
clear
B)
Rs. 4.00 done
clear
C)
Rs. 0.25 done
clear
D)
Rs. 0.60 done
clear
View Solution play_arrow
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question_answer73)
4 bulbs marked 40 W, 250 V are connected in series with 250 V mains. The total power is [EAMCET (Engg.) 1995]
A)
10 W done
clear
B)
40 W done
clear
C)
320 W done
clear
D)
160 W done
clear
View Solution play_arrow
-
question_answer74)
Pick out the wrong statement [AMU 1995]
A)
In a simple battery circuit, the point of lowest potential is the negative terminal of the battery done
clear
B)
The resistance of an incandescent lamp is greater when the lamp is switched off done
clear
C)
An ordinary 100 W lamp has less resistance than a 60 W lamp done
clear
D)
At constant voltage, the heat developed in a uniform wire varies inversely as the length of the wire used done
clear
View Solution play_arrow
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question_answer75)
Two resistors of \[6\,\Omega \] and \[9\Omega \] are connected in series to a 120 volt source. The power consumed by the \[6\,\Omega \] resistor is [SCRA 1994]
A)
384 W done
clear
B)
576 W done
clear
C)
1500 W done
clear
D)
1200 W done
clear
View Solution play_arrow
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question_answer76)
Electric room radiator which operates at 225 volts has resistance of 50 ohms. Power of the radiator is approximately [SCRA 1994]
A)
100 W done
clear
B)
450 W done
clear
C)
750 W done
clear
D)
1000 W done
clear
View Solution play_arrow
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question_answer77)
If a power of 100 W is being supplied across a potential difference of 200 V, current flowing is [AFMC 1993]
A)
2 A done
clear
B)
0.5 A done
clear
C)
1 A done
clear
D)
20 A done
clear
View Solution play_arrow
-
question_answer78)
A current of 2 A passing through conductor produces 80 J of heat in 10 seconds. The resistance of the conductor is [CBSE PMT 1993]
A)
\[0.5\,\Omega \] done
clear
B)
\[2\,\Omega \] done
clear
C)
\[4\,\Omega \] done
clear
D)
\[20\,\Omega \] done
clear
View Solution play_arrow
-
question_answer79)
A \[4\mu F\] conductor is charged to 400 volts and then its plates are joined through a resistance of \[1\,k\Omega \]. The heat produced in the resistance is [CBSE PMT 1994]
A)
0.16 J done
clear
B)
1.28 J done
clear
C)
0.64 J done
clear
D)
0.32 J done
clear
View Solution play_arrow
-
question_answer80)
A 10 ohm electric heater operates on a 110 V line. Calculate the rate at which it develops heat in watts [AFMC 1997]
A)
1310 W done
clear
B)
670 W done
clear
C)
810 W done
clear
D)
1210 W done
clear
View Solution play_arrow
-
question_answer81)
A (100 W, 200 V) bulb is connected to a 160 V power supply. The power consumption would be [CBSE PMT 1997; JIPMER 2000]
A)
64 W done
clear
B)
80 W done
clear
C)
100 W done
clear
D)
125 W done
clear
View Solution play_arrow
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question_answer82)
A battery of e.m.f. 10 V and internal resistance 0.5 ohm is connected across a variable resistance R. The value of R for which the power delivered in it is maximum is given by [BHU 1998; JIPMER 2001, 02; CBSE PMT 2001]
A)
2.0 ohm done
clear
B)
0.25 ohm done
clear
C)
1.0 ohm done
clear
D)
0.5 ohm done
clear
View Solution play_arrow
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question_answer83)
A piece of fuse wire melts when a current of 15 ampere flows through it. With this current, if it dissipates 22.5 W, the resistance of fuse wire will be [MNR 1998]
A)
Zero done
clear
B)
\[10\,\Omega \] done
clear
C)
\[1\,\Omega \] done
clear
D)
\[0.10\,\Omega \] done
clear
View Solution play_arrow
-
question_answer84)
Two wires 'A' and 'B' of the same material have their lengths in the ratio 1 : 2 and radii in the ratio 2 : 1. The two wires are connected in parallel across a battery. The ratio of the heat produced in ?A? to the heat produced in ?B? for the same time is [MNR 1998]
A)
\[1:2\] done
clear
B)
\[2:1\] done
clear
C)
\[1:8\] done
clear
D)
\[8:1\] done
clear
View Solution play_arrow
-
question_answer85)
A heater draws a current of 2A when connected to a 250V source. The rate of energy dissipation is [JIPMER 1999]
A)
500 W done
clear
B)
1000 W done
clear
C)
250 W done
clear
D)
125 W done
clear
View Solution play_arrow
-
question_answer86)
A bulb rated at (100W ? 200V) is used on a 100V line. The current in the bulb is [JIPMER 1999]
A)
\[\frac{1}{4}\]amp done
clear
B)
4 amp done
clear
C)
\[\frac{1}{2}\]amp done
clear
D)
2 amp done
clear
View Solution play_arrow
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question_answer87)
A steel wire has a resistance twice that of an aluminium wire. Both of them are connected with a constant voltage supply. More heat will be dissipated in [Roorkee 1999]
A)
Steel wire when both are connected in series done
clear
B)
Steel wire when both are connected in parallel done
clear
C)
Aluminium wire when both are connected in series done
clear
D)
Aluminium wire when both are connected in parallel done
clear
View Solution play_arrow
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question_answer88)
A current i passes through a wire of length l, radius of cross-section r and resistivity r. The rate of heat generation is [AMU (Med.) 1999]
A)
\[\frac{{{i}^{2}}l\rho }{\pi {{r}^{2}}}\] done
clear
B)
\[{{i}^{2}}{{\left( \frac{l\rho }{\pi {{r}^{2}}} \right)}^{2}}\] done
clear
C)
\[{{i}^{2}}l\,\rho \,/\,r\] done
clear
D)
\[i\,l\,\rho \,/\,r\] done
clear
View Solution play_arrow
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question_answer89)
Which of the following is not equal to watt [DPMT 1999]
A)
\[{{(Amp)}^{\,2}}\times ohm\] done
clear
B)
Amp / Volt done
clear
C)
Amp × Volt done
clear
D)
Joule / sec done
clear
View Solution play_arrow
-
question_answer90)
Two wires with resistances R and 2R are connected in parallel, the ratio of heat generated in 2R and R is [DCE 1999, 2000]
A)
1 : 2 done
clear
B)
2 : 1 done
clear
C)
1 : 4 done
clear
D)
4 : 1 done
clear
View Solution play_arrow
-
question_answer91)
If a high power heater is connected to electric mains, then the bulbs in the house become dim, because there is a [BHU 1999; Pb. PMT 2000]
A)
Current drop done
clear
B)
Potential drop done
clear
C)
No current drop done
clear
D)
No potential drop done
clear
View Solution play_arrow
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question_answer92)
If three bulbs 60W, 100W and 200W are connected in parallel, then [BHU 2000]
A)
200 W bulb will glow more done
clear
B)
60 W bulb will glow more done
clear
C)
100 W bulb will glow more done
clear
D)
All the bulbs will glow equally done
clear
View Solution play_arrow
-
question_answer93)
An expression for rate of heat generated, if a current of I ampere flows through a resistance of R W, is [Pb. PMT 2000]
A)
\[{{I}^{2}}Rt\] done
clear
B)
\[{{I}^{2}}R\] done
clear
C)
\[{{V}^{2}}R\] done
clear
D)
\[I\ R\] done
clear
View Solution play_arrow
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question_answer94)
On giving 220V to a resistor the power dissipated is 40W then value of resistance is [RPMT 2000]
A)
1210 W done
clear
B)
2000 W done
clear
C)
1000 W done
clear
D)
None of these done
clear
View Solution play_arrow
-
question_answer95)
A 60 watt bulb operates on 220V supply. The current flowing through the bulb is [MP PMT 2000]
A)
11/3 amp done
clear
B)
3/11 amp done
clear
C)
3 amp done
clear
D)
6 amp done
clear
View Solution play_arrow
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question_answer96)
If two bulbs of wattage 25 and 30, each rated at 220 volts, are connected in series with a 440 volt supply, which bulb will fuse [MP PET 2000]
A)
25 W bulb done
clear
B)
30 W bulb done
clear
C)
Neither of them done
clear
D)
Both of them done
clear
View Solution play_arrow
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question_answer97)
Two electric bulbs (60W and 100W respectively) are connected in series. The current passing through them is [AMU (Med.) 2000]
A)
More in 100W bulb done
clear
B)
More in 60W bulb done
clear
C)
Same in both done
clear
D)
None of these done
clear
View Solution play_arrow
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question_answer98)
In the circuit shown below, the power developed in the 6W resistor is 6 watt. The power in watts developed in the 4W resistor is [AMU (Med.) 2000]
A)
16 done
clear
B)
9 done
clear
C)
6 done
clear
D)
4 done
clear
View Solution play_arrow
-
question_answer99)
Two wires A and B of same material and mass have their lengths in the ratio 1 : 2. On connecting them to the same source, the rate of heat dissipation in B is found to be 5W. The rate of heat dissipation in A is [AMU (Engg.) 2000]
A)
10W done
clear
B)
5W done
clear
C)
20W done
clear
D)
None of these done
clear
View Solution play_arrow
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question_answer100)
If two electric bulbs have 40W and 60W rating at \[220V\], then the ratio of their resistances will be [BHU 1999; KCET 2001]
A)
3 : 2 done
clear
B)
2 : 3 done
clear
C)
3 : 4 done
clear
D)
4 : 3 done
clear
View Solution play_arrow
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question_answer101)
An electric bulb is designed to draw power P0 at voltage V0. If the voltage is V it draws a power P. Then [KCET 2001]
A)
\[P={{\left( \frac{{{V}_{0}}}{V} \right)}^{2}}{{P}_{0}}\] done
clear
B)
\[P={{\left( \frac{V}{{{V}_{0}}} \right)}^{2}}{{P}_{0}}\] done
clear
C)
\[P=\left( \frac{V}{{{V}_{0}}} \right)\,{{P}_{0}}\] done
clear
D)
\[P=\left( \frac{{{V}_{0}}}{V} \right)\,{{P}_{0}}\] done
clear
View Solution play_arrow
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question_answer102)
Three bulbs of 40W, 60W and 100W are arranged in series with 220V. Which bulb has minimum resistance [AFMC 2001]
A)
40W done
clear
B)
60W done
clear
C)
100W done
clear
D)
Equal in all bulbs done
clear
View Solution play_arrow
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question_answer103)
An electric kettle has two heating coils. When one coil is used, water in the kettle boils in 5 minutes, while when second coil is used, same water boils in 10 minutes. If the two coils, connected in parallel are used simultaneously, the same water will boil in time [MP PET 2001]
A)
3 min 20 sec done
clear
B)
5 min done
clear
C)
7 min 30 sec done
clear
D)
2 min 30 sec done
clear
View Solution play_arrow
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question_answer104)
An external resistance R is connected to a battery of e.m.f. V and internal resistance r. The joule heat produced in resistor R is maximum when R is equal to [MP PET 2001]
A)
r done
clear
B)
\[\frac{r}{2}\] done
clear
C)
2r done
clear
D)
Infinitely large done
clear
View Solution play_arrow
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question_answer105)
The amount of heat produced in a resistor when a current is passed through it can be found using [Kerala PET 2001]
A)
Faraday?s Law done
clear
B)
Kirchhoff?s Law done
clear
C)
Laplace?s Law done
clear
D)
Joule?s Law done
clear
View Solution play_arrow
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question_answer106)
Two wires have resistance of 2W and 4W connected to same voltage, ratio of heat dissipated at resistance is [UPSEAT 2001]
A)
1 : 2 done
clear
B)
4 : 3 done
clear
C)
2 : 1 done
clear
D)
5 : 2 done
clear
View Solution play_arrow
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question_answer107)
Two electric bulbs rated \[{{P}_{1}}\] watt V volts and \[{{P}_{2}}\] watt V volts are connected in parallel and V volts are applied to it. The total power will be [MP PMT 2001; MP PET 2002]
A)
\[{{P}_{1}}+{{P}_{2}}watt\] done
clear
B)
\[\sqrt{{{P}_{1}}{{P}_{2}}}\]watt done
clear
C)
\[\frac{{{P}_{1}}{{P}_{2}}}{{{P}_{1}}+{{P}_{2}}}watt\] done
clear
D)
\[\frac{{{P}_{1}}+{{P}_{2}}}{{{P}_{1}}{{P}_{2}}}watt\] done
clear
View Solution play_arrow
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question_answer108)
n identical bulbs, each designed to draw a power p from a certain voltage supply, are joined in series across that supply. The total power which they will draw is [KCET 2002]
A)
\[p/{{n}^{2}}\] done
clear
B)
\[p/n\] done
clear
C)
\[p\] done
clear
D)
\[np\] done
clear
View Solution play_arrow
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question_answer109)
A wire when connected to 220V mains supply has power dissipation \[{{P}_{1}}\]. Now the wire is cut into two equal pieces which are connected in parallel to the same supply. Power dissipation in this case is \[{{P}_{2}}\]. Then \[{{P}_{2}}:{{P}_{1}}\] is [AIEEE 2002]
A)
1 done
clear
B)
4 done
clear
C)
2 done
clear
D)
3 done
clear
View Solution play_arrow
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question_answer110)
An electric bulb marked 40 W and 200 V, is used in a circuit of supply voltage 100 V. Now its power is [AIIMS 2002]
A)
100W done
clear
B)
40W done
clear
C)
20W done
clear
D)
10W done
clear
View Solution play_arrow
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question_answer111)
Electric bulb 50 W-100 V glowing at full power are to be used in parallel with battery 120 V, 10 W. Maximum number of bulbs that can be connected so that they glow in full power is [CPMT 2002]
A)
2 done
clear
B)
8 done
clear
C)
4 done
clear
D)
6 done
clear
View Solution play_arrow
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question_answer112)
A bulb has specification of one kilowatt and 250 volts, the resistance of bulb is [MP PMT 2002]
A)
125 W done
clear
B)
62.5 W done
clear
C)
0.25 W done
clear
D)
625 W done
clear
View Solution play_arrow
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question_answer113)
If a 30 V, 90 W bulb is to be worked on a 120 V line, a resistance of how many ohms should be connected in series with the bulb [MP PMT 2002; KCET 2003]
A)
10 ohm done
clear
B)
20 ohm done
clear
C)
30 ohm done
clear
D)
40 ohm done
clear
View Solution play_arrow
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question_answer114)
A fuse wire with radius 1 mm blows at 1.5 amp. The radius of the fuse wire of the same material to blow at 3A will be [KCET 2003]
A)
\[{{4}^{1/3}}mm\] done
clear
B)
\[{{3}^{1/4}}mm\] done
clear
C)
\[{{2}^{1/2}}mm\] done
clear
D)
\[{{3}^{1/2}}mm\] done
clear
View Solution play_arrow
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question_answer115)
Three electric bulbs of rating 60W each are joined in series and then connected to electric mains. The power consumed by these three bulbs will be [MP PET 2003; CBSE PMT 2004]
A)
180 W done
clear
B)
60 W done
clear
C)
20 W done
clear
D)
\[\frac{20}{3}W\] done
clear
View Solution play_arrow
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question_answer116)
An electric bulb is rated 60W, 220V. The resistance of its filament is [MP PET 2003]
A)
708 W done
clear
B)
870 W done
clear
C)
807 W done
clear
D)
780 W done
clear
View Solution play_arrow
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question_answer117)
A 220 volt, 1000 W bulb is connected across a 110 volt mains supply. The power consumed will be [AIEEE 2003]
A)
1000 W done
clear
B)
750 W done
clear
C)
500 W done
clear
D)
250 W done
clear
View Solution play_arrow
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question_answer118)
Two bulbs of 100 W and 200 W working at 220 volt are joined in series with 220 volt supply. Total power consumed will be approximately. [Pb. PET 2003; BHU 2005]
A)
65 watt done
clear
B)
33 watt done
clear
C)
300 watt done
clear
D)
100 watt done
clear
View Solution play_arrow
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question_answer119)
How many calories of heat will be produced approximately in a 210 watt electric bulb in 5 minutes [Pb. PET 2004]
A)
80000 cal done
clear
B)
63000 cal done
clear
C)
1050 cal done
clear
D)
15000 cal done
clear
View Solution play_arrow
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question_answer120)
\[A\,\,{{5}^{o}}C\] rise in the temperature is observed in a conductor by passing some current. When the current is doubled, then rise in temperature will be equal to [BHU 2004]
A)
\[{{5}^{o}}C\] done
clear
B)
\[{{10}^{o}}C\] done
clear
C)
\[{{20}^{o}}C\] done
clear
D)
\[{{40}^{o}}C\] done
clear
View Solution play_arrow
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question_answer121)
If a 2 kW boiler is used everyday for 1 hour, then electrical energy consumed by boiler in thirty days is [BHU 2004]
A)
15 unit done
clear
B)
60 unit done
clear
C)
120 unit done
clear
D)
240 unit done
clear
View Solution play_arrow
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question_answer122)
What will happen when a 40 watt, 220 volt lamp and 100 watt, 220 volt lamp are connected in series across 40 volt supply [BHU 2004]
A)
100 watt lamp will fuse done
clear
B)
40 watt lamp will fuse done
clear
C)
Both lamps will fuse done
clear
D)
Neither lamp will fuse done
clear
View Solution play_arrow
-
question_answer123)
What is the ratio of heat generated in R and 2R [DCE 2003]
A)
2 : 1 done
clear
B)
1 : 2 done
clear
C)
4 : 1 done
clear
D)
1 : 4 done
clear
View Solution play_arrow
-
question_answer124)
In an electric heater 4 amp current passes for 1 minute at potential difference of 250 volt, the power of heater and energy consumed will be respectively [DPMT 2003]
A)
1 kW, 60 kJ done
clear
B)
0.5 kW, 30 kJ done
clear
C)
10 kW, 600 kJ done
clear
D)
None of these done
clear
View Solution play_arrow
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question_answer125)
Some electric bulbs are connected in series across a 220 V supply in a room. If one bulb is fused then remaining bulbs are connected again in series across the same supply. The illumination in the room will [J & K CET 2004]
A)
Increase done
clear
B)
Decrease done
clear
C)
Remains the same done
clear
D)
Not continuous done
clear
View Solution play_arrow
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question_answer126)
The resistor of resistance 'R' is connected to 25 V supply and heat produced in it is 25 J/sec. The value of R is [Orissa PMT 2004]
A)
\[225\Omega \] done
clear
B)
\[1\Omega \] done
clear
C)
\[25\Omega \] done
clear
D)
\[50\Omega \] done
clear
View Solution play_arrow
-
question_answer127)
Three bulbs of 40 W, 60 W, 100 W are arranged in series with 220 volt supply which bulb has minimum resistance [Pb. PET 2000]
A)
100 W done
clear
B)
40 W done
clear
C)
60 W done
clear
D)
Equal in all bulbs done
clear
View Solution play_arrow
-
question_answer128)
If two electric bulbs have 40 W and 60 W rating at 220 V, then the ratio of their resistances will be [Pb. PET 2001]
A)
9 : 4 done
clear
B)
4 : 3 done
clear
C)
3 : 8 done
clear
D)
3 : 2 done
clear
View Solution play_arrow
-
question_answer129)
A 10 V storage battery of negligible internal resistance is connected across a \[50\,\Omega \] resistor. How much heat energy is produced in the resistor in 1 hour [Pb. PET 2001]
A)
7200 J done
clear
B)
6200 J done
clear
C)
5200 J done
clear
D)
4200 J done
clear
View Solution play_arrow
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question_answer130)
A hot electric iron has a resistance of \[80\,\Omega \] and is used on a 200 V source. The electrical energy spent, if it is used for two hours, will be [Pb. PET 2002]
A)
8000 Wh done
clear
B)
2000 Wh done
clear
C)
1000 Wh done
clear
D)
800 Wh done
clear
View Solution play_arrow
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question_answer131)
The heat produced by a 100 watt heater in 2 minute will be equal to [BCECE 2004]
A)
\[12\times {{10}^{3}}\,J\] done
clear
B)
\[10\times {{10}^{3}}\,J\] done
clear
C)
\[6\times {{10}^{3}}\,J\] done
clear
D)
\[3\times {{10}^{3}}\,J\] done
clear
View Solution play_arrow
-
question_answer132)
If two wires having resistance R and 2R. Both joined in series and in parallel then ratio of heat generated in this situation, applying the same voltage, [BCECE 2004]
A)
2 : 1 done
clear
B)
1 : 2 done
clear
C)
2 : 9 done
clear
D)
9 : 2 done
clear
View Solution play_arrow
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question_answer133)
Two electric bulbs A and B are rated as 60 W and 100 W. They are connected in parallel to the same source. Then, [KCET 2004]
A)
Both draw the same current done
clear
B)
A draws more current than B done
clear
C)
B draws more current than A done
clear
D)
Current drawn are in the ratio of their resistances done
clear
View Solution play_arrow
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question_answer134)
Three identical resistances A, B and C are connected as shown in the given figure. The heat produced will be maximum [MP PMT 2004]
A)
In B done
clear
B)
In B and C done
clear
C)
In A done
clear
D)
Same for A, B and C done
clear
View Solution play_arrow
-
question_answer135)
If 2.2kW power is transmitted through a \[100\Omega \] line at \[22,000V,\] the power loss in the form of heat will be [MP PET 2004]
A)
0.1 W done
clear
B)
1 W done
clear
C)
10 W done
clear
D)
100 W done
clear
View Solution play_arrow
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question_answer136)
A heater coil connected to a supply of a 220 V is dissipating some power \[{{P}_{1}}.\] The coil is cut into half and the two halves are connected in parallel. The heater now dissipates a power \[{{P}_{2}}.\] The ratio of power \[{{P}_{1}}\,\,:\,\,{{P}_{2}}\] is [AFMC 2004]
A)
2 : 1 done
clear
B)
1 : 2 done
clear
C)
1 : 4 done
clear
D)
4 : 1 done
clear
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question_answer137)
An electric lamp is marked 60 W, 230 V. The cost of a 1 kWh of energy is Rs. 1.25. The cost of using this lamp 8 hrs a day for 30 day is [Kerala (Med.) 2002]
A)
Rs. 10 done
clear
B)
Rs. 16 done
clear
C)
Rs. 18 done
clear
D)
Rs. 20 done
clear
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question_answer138)
An electric iron draws 5 amp, a TV set draws 3 amp and refrigerator draws 2 amp from a 220 volt main line. The three appliances are connected in parallel. If all the three are operating at the same time, the fuse used may be of [ISM Dhanbad 1994]
A)
20 amp done
clear
B)
5 amp done
clear
C)
15 amp done
clear
D)
10 amp done
clear
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question_answer139)
Match the List I with the List II from the combination shown. In the left side (List I) there are four different conditions and in the right side (List II), there are ratios of heat produced in each resistance for each condition : [ISM Dhanbad 1994]
|
List I |
List II |
(I) |
Two wires of same resistance are connected in series and same current is passed through them |
(A) 1 : 2 |
(II) |
Two wires of resistance R and 2R ohm are connected in series and same P.D. is applied across them |
(B) 4 : 1 |
(III) |
Two wires of same resistance are connected in parallel and same current is flowing through them |
(C) 1 : 1 |
(IV) |
Two wires of resistances in the ratio 1 : 2 are connected in parallel and same P.D. is applied across them |
(D) 2 : 1 |
A)
\[I-B;\ II-A;\ III-C;\ IV-D\] done
clear
B)
\[I-C;\ II-D;\ III-C;\ IV-D\] done
clear
C)
\[I-B;\ II-D;\ III-A;\ IV-C\] done
clear
D)
\[I-A;\ II-B;\ III-D;\ IV-C\] done
clear
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question_answer140)
The electric current passing through a metallic wire produces heat because of [BHU 1994]
A)
Collisions of conduction electrons with each other done
clear
B)
Collisions of the atoms of the metal with each other done
clear
C)
The energy released in the ionization of the atoms of the metal done
clear
D)
Collisions of the conduction electrons with the atoms of the metallic wires done
clear
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question_answer141)
The maximum current that flows through a fuse wire before it blows out varies with its radius as [SCRA 1998]
A)
\[{{r}^{3/2}}\] done
clear
B)
r done
clear
C)
\[{{r}^{2/3}}\] done
clear
D)
\[{{r}^{1/2}}\] done
clear
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question_answer142)
What is immaterial for an electric fuse wire [UPSEAT 1999]
A)
Specific resistance of the wire done
clear
B)
Radius of the wire done
clear
C)
Length of the wire done
clear
D)
Current flowing through the wire done
clear
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question_answer143)
The current flowing through a lamp marked as 50 W and 250 V is [MH CET (Med.) 2001]
A)
5 amp done
clear
B)
2.5 amp done
clear
C)
2 amp done
clear
D)
0.2 amp done
clear
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question_answer144)
Find the power of the circuit [AIEEE 2002]
A)
1.5 W done
clear
B)
2 W done
clear
C)
1 W done
clear
D)
None of these done
clear
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question_answer145)
If in the circuit, power dissipation is 150 W, then R is [AIEEE 2002]
A)
2 W done
clear
B)
6 W done
clear
C)
5 W done
clear
D)
4 W done
clear
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question_answer146)
Two resistors whose value are in ratio 2 : 1 are connected in parallel with one cell. Then ratio of power dissipated is [RPMT 2000]
A)
2 : 1 done
clear
B)
4 : 1 done
clear
C)
1 : 2 done
clear
D)
1 : 1 done
clear
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question_answer147)
A heater coil is cut into two equal parts and only one part is now used in the heater. The heat generated will now be [AIEEE 2005]
A)
One fourth done
clear
B)
Halved done
clear
C)
Doubled done
clear
D)
Four times done
clear
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question_answer148)
The resistance of hot tungsten filament is about 10 times the cold resistance. What will be the resistance of 100 W and 200 V lamp when not in use [AIEEE 2005]
A)
\[400\,\Omega \] done
clear
B)
\[200\,\Omega \] done
clear
C)
\[40\text{ }\Omega \] done
clear
D)
\[20\,\Omega \] done
clear
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question_answer149)
A 5.0 amp current is setup in an external circuit by a 6.0 volt storage battery for 6.0 minutes. The chemical energy of the battery is reduced by [KCET 2005]
A)
1.08 ´ 104 J done
clear
B)
1.08 ´ 10-4 volt done
clear
C)
1.8 ´ 104 J done
clear
D)
1.8 ´ 104 volt done
clear
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question_answer150)
A railway compartment is lit up by thirteen lamps each taking 2.1 amp at 15 volts. The heat generated per second in each lamp will be [J & K CET 2005]
A)
\[4.35\,cal\] done
clear
B)
\[5.73\,\,cal\] done
clear
C)
\[7.5\,\,cal\] done
clear
D)
\[2.5\,cal\] done
clear
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question_answer151)
Two bulbs X and Y having same voltage rating and of power 40 watt and 60 watt respectively are connected in series across a potential difference of 300 volt, then [Orissa JEE 2005]
A)
X will glow brighter done
clear
B)
Resistance of Y is greater than X done
clear
C)
Heat produced in Y will be greater than X done
clear
D)
Voltage drop in X will be greater than Y done
clear
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question_answer152)
3 identical bulbs are connected in series and these together dissipate a power P. If now the bulbs are connected in parallel, then the power dissipated will be [DPMT 2005]
A)
\[\frac{P}{3}\] done
clear
B)
3P done
clear
C)
9P done
clear
D)
\[\frac{P}{9}\] done
clear
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question_answer153)
A coil takes 15 min to boil a certain amount of water, another coil takes 20 min for the same process. Time taken to boil the same amount of water when both coil are connected in series [DCE 2005]
A)
5 min done
clear
B)
8.6 min done
clear
C)
35 min done
clear
D)
30 min done
clear
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