question_answer 1)
Lighting is an electrical discharge caused by imbalanced between
A)
clouds and the ground done
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B)
within the clouds done
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C)
Both a and b done
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D)
None of these done
clear
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question_answer 2)
Electric current has both magnitude and direction it is a:
A)
vector quantity done
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B)
scalar quantity done
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C)
tensor quantity done
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D)
None of these done
clear
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question_answer 3)
Conventional current flows from
A)
point of higher potential to lower potential done
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B)
point of lower potential to higher potential done
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C)
point of lower potential to lower potential done
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D)
all of the above done
clear
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question_answer 4)
One coulomb per second is equal to:
A)
1 farad done
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B)
1 ampere done
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C)
1 volt done
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D)
None of these done
clear
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question_answer 5)
A charge of 60 C passes through an electric lamp in 2 minutes. Then the current in the lamp is:
A)
30 A done
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B)
1 A done
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C)
0.5 A done
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D)
5 A done
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question_answer 6)
Charge through a conductor is given as a function of time t as \[q=4{{t}^{2}}+4t+4\] coulomb. At 2 s what is the current flowing?
A)
12 A done
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B)
8 A done
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C)
20 A done
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D)
28 A done
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question_answer 7)
Charge through a cross-section of a conductor is given by \[Q=5{{t}^{2}}-2t\]. It coulomb. Find the average current through the conductor in the interval \[{{t}_{1}}=2\,s\]to\[{{t}_{2}}=4\,s\].
A)
14 A done
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B)
28A done
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C)
56 A done
clear
D)
7 A done
clear
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question_answer 8)
The current in a wire varies with time according to the equation\[l=4+2t\], where, l is an ampere and f is in second. The quantity of charge which has to be passed through a cross-section of the wire during the time t =2s to t = 6s is:
A)
40 C done
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B)
48 C done
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C)
38 C done
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D)
43 C done
clear
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question_answer 9)
An electric charge will experience a ........... when an electric field is applied.
A)
pressure done
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B)
momentum done
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C)
force done
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D)
None of these done
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question_answer 10)
In earth's atmosphere where do the free charged particles exist?
A)
ionosphere done
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B)
mesosphere done
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C)
troposphere done
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D)
stratosphere done
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question_answer 11)
Mechanisms which maintain a steady electric field are:
A)
cells done
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B)
batteries done
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C)
Both (a) and (b) done
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D)
None of these done
clear
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question_answer 12)
In the current against voltage curve in Ohm's law, the slope gives:
A)
resistance done
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B)
conductance done
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C)
resistivity done
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D)
conductivity done
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question_answer 13)
The electrical resistance of a conductor depends upon:
A)
size of the conductor done
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B)
temperature of the conductor done
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C)
geometry of the conductor done
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D)
All of the above done
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question_answer 14)
The voltage V and current l graphs for a conductor at two different temperatures \[{{T}_{1}}\]and \[{{T}_{2}}\]are shown in the figure. The relation between \[{{T}_{1}}\]and \[{{T}_{2}}\]is:
A)
\[{{T}_{1}}>{{T}_{2}}\] done
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B)
\[{{T}_{1}}<{{T}_{2}}\] done
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C)
\[{{T}_{1}}={{T}_{2}}\] done
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D)
\[{{T}_{1}}=\frac{1}{{{T}_{2}}}\] done
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question_answer 15)
A 220 V main supply is connected to a resistance of\[100\,k\Omega \]. The effective current is
A)
\[2.2\,mA\] done
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B)
\[2.2\sqrt{2}\,mA\] done
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C)
\[\frac{2.2}{\sqrt{2}}\,mA\] done
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D)
None of these done
clear
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question_answer 16)
Consider a current carrying wire (current I) in the shape of a circle. Note that as the current progresses along the wire, the direction of \[\overrightarrow{J}\] (current density) changes in an exact manner, while the current / remains unaffected. The agent that is essentially responsible for it is: (NCERT EXEMPLAR)
A)
source of emf done
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B)
electric field produced by charges accumulated on the surface of wire done
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C)
the charges just behind a given segment of wire which push them just right way by repulsion done
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D)
the charges ahead done
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question_answer 17)
In the diagram shown, the reading of voltmeter is 20 V and that of ammeter is 4 A. The value of R should be (Consider given ammeter and voltmeter are not ideal):
A)
equal to \[5\Omega \] done
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B)
greater than \[5\Omega \] done
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C)
less than \[5\Omega \] done
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D)
greater or less than \[5\Omega \] done
clear
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question_answer 18)
There are three copper wires of equal length and the ratio of their radii is \[1:2:3\]. What is the ratio of their resistivity?
A)
\[1:2:3\] done
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B)
\[3:2:1\] done
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C)
\[1:1:1\] done
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D)
\[1:4:9\] done
clear
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question_answer 19)
The condition for the validity of Ohm's law is that the:
A)
temperature should remain constant done
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B)
current should be proportional to voltage done
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C)
resistance must be wire wound type done
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D)
all of the above done
clear
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question_answer 20)
The unit of specific conductivity is:
A)
\[\Omega -c{{m}^{-1}}\] done
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B)
\[\Omega -c{{m}^{2}}\] done
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C)
\[{{\Omega }^{-1}}cm\] done
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D)
\[{{\Omega }^{-1}}c{{m}^{-1}}\] done
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question_answer 21)
A metal rod of Length 10 cm and a rectangular cross-section of \[\text{1}\,\text{cm }\!\!\times\!\!\text{ }\frac{\text{1}}{\text{2}}\] is connected to a battery across opposite faces. The resistance will be: (NCERT EXEMPLAR)
A)
maximum when the battery is connected across \[\text{1}\,\text{cm }\!\!\times\!\!\text{ }\frac{\text{1}}{\text{2}}\] faces done
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B)
maximum when the battery is connected across \[\text{10}\,\text{cm }\!\!\times\!\!\text{ 1}\,\text{cm}\]faces done
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C)
maximum when the battery is connected across \[\text{10}\,\text{cm }\!\!\times\!\!\text{ }\frac{\text{1}}{2}\,\text{cm}\] faces done
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D)
same irrespective of the three faces done
clear
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question_answer 22)
The resistance of a wire is \[10\Omega \]. What will be the new resistance, if it is stretched uniformly 8 times its original length?
A)
\[640\,\Omega \] done
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B)
\[64\,\Omega \] done
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C)
\[10\,\Omega \] done
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D)
\[6400\,\Omega \] done
clear
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question_answer 23)
A cylindrical rod is reformed to half of its original Length keeping volume constant. If its resistance before this change were R, then the resistance after reformation of rod will be:
A)
R done
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B)
R/4 done
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C)
3R/4 done
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D)
R/2 done
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question_answer 24)
The conductivity of a metal decreases with the increase in temperature on account of: (CBSE 2020)
A)
decrease in number density of electrons done
clear
B)
decrease in resistivity done
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C)
decrease in relaxation time done
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D)
increase in mean free path done
clear
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question_answer 25)
The figure shows three cylindrical copper conductors along with their face areas and lengths. Rank them according to the current through them, greatest first when the same potential difference V is placed across their lengths.
A)
\[{{i}_{l}}={{i}_{ll}}={{i}_{lll}}\] done
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B)
\[{{i}_{l}}>{{i}_{ll}}>{{i}_{lll}}\] done
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C)
\[{{i}_{l}}<{{i}_{ll}}<{{i}_{lll}}\] done
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D)
\[({{i}_{l}}={{i}_{lll}})<{{i}_{ll}}\] done
clear
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question_answer 26)
When there is an electric current through a conducting wire along its length, then an electric field must exist:
A)
outside the wire but normal to it done
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B)
outside the wire but parallel to it done
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C)
inside the wire but parallel to it done
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D)
inside the wire but normal to it done
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question_answer 27)
Which of the following characteristics of electrons determines the current in a conductor? (NCERT EXEMPLAR)
A)
Drift velocity alone done
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B)
Thermal velocity alone done
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C)
Both drift velocity and thermal velocity done
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D)
Neither drift nor thermal velocity done
clear
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question_answer 28)
Drift velocity \[{{\text{v}}_{\text{d}}}\] varies with the intensity of electric field as per the relation:
A)
\[{{\text{v}}_{\text{d}}}\propto E\] done
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B)
\[{{\text{v}}_{\text{d}}}\propto \frac{1}{E}\] done
clear
C)
\[{{\text{v}}_{\text{d}}}\text{=constant}\] done
clear
D)
\[{{\text{v}}_{\text{d}}}\propto {{E}^{2}}\] done
clear
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question_answer 29)
The unit of mobility is
A)
\[m{{s}^{-1}}\] done
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B)
\[m{{s}^{-1}}V\] done
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C)
\[{{m}^{2}}{{V}^{-1}}{{s}^{-1}}\] done
clear
D)
\[{{m}^{2}}{{V}^{-1}}s\] done
clear
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question_answer 30)
A steady current flows in a metallic conductor of non-uniform cross-section. The quantity/quantities constant along the length of the conductor is/are:
A)
current, electric field and drift speed done
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B)
drift speed only done
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C)
current and drift speed done
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D)
current only done
clear
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question_answer 31)
A charged particle having drift velocity of \[7.5\times {{10}^{-4}}m{{s}^{-1}}\] in electric field of \[3\times {{10}^{-10}}V{{m}^{-1}}\], mobility is:
A)
\[6.5\times {{10}^{6}}{{m}^{2}}{{V}^{-1}}{{s}^{-1}}\] done
clear
B)
\[2.5\times {{10}^{6}}{{m}^{2}}{{V}^{-1}}{{s}^{-1}}\] done
clear
C)
\[2.5\times {{10}^{4}}{{m}^{2}}{{V}^{-1}}{{s}^{-1}}\] done
clear
D)
\[6.5\times {{10}^{4}}{{m}^{2}}{{V}^{-1}}{{s}^{-1}}\] done
clear
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question_answer 32)
The resistance of a metal wire increases with increasing temperature on account of: (CBSE 2020)
A)
decrease in free electron density done
clear
B)
decrease in relaxation time done
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C)
increase in mean free path done
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D)
increase in the mass of electron done
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question_answer 33)
The dimensions of mobility of charge carriers are:
A)
\[\left[ {{M}^{-2}}{{T}^{2}}A \right]\] done
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B)
\[\left[ {{M}^{-1}}{{T}^{2}}A \right]\] done
clear
C)
\[\left[ {{M}^{-2}}{{T}^{3}}A \right]\] done
clear
D)
\[\left[ {{M}^{-1}}{{T}^{3}}A \right]\] done
clear
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question_answer 34)
Which of the following I-V graph represents ohmic conductors?
A)
B)
C)
D)
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question_answer 35)
Ohm's Law is not applicable to:
A)
dc circuits done
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B)
high currents done
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C)
small resistors done
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D)
semi-conductors done
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question_answer 36)
The I-V characteristics shown In figure represents:
A)
ohmic conductors done
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B)
non-ohmic conductors done
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C)
insulators done
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D)
superconductors done
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question_answer 37)
Ohm's law fails in:
A)
Diode done
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B)
Thyristor done
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C)
PN junction system done
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D)
All of these done
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question_answer 38)
Range of resistivity for metals is:
A)
\[{{10}^{-6}}\Omega m\text{ }to\text{ }{{10}^{-4}}\Omega m\] done
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B)
\[{{10}^{-7}}\Omega m\text{ }to\text{ }{{10}^{-5}}\Omega m\] done
clear
C)
\[{{10}^{-8}}\Omega m\text{ }to\text{ }{{10}^{-6}}\Omega m\] done
clear
D)
\[{{10}^{-9}}\Omega m\text{ }to\text{ }{{10}^{-7}}\Omega m\] done
clear
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question_answer 39)
Which meterial is expected to have least resistivity?
A)
Copper done
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B)
Lead done
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C)
Mercury done
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D)
Zinc done
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question_answer 40)
A copper wire is stretched to make it 0.2%. What is the percentage change in its resistivity?
A)
0.4% done
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B)
2.0% done
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C)
4.0% done
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D)
None of these done
clear
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question_answer 41)
Arrange the following materials in increasing order of their resistivity: Nichrome, Copper, Germanium, Silicon
A)
Copper < Nichrome < Germanium < Silicon done
clear
B)
Germanium < Copper < Nichrome < Silicon done
clear
C)
Nichrome < Copper < Germanium < Silicon done
clear
D)
Silicon < Nichrome < Germanium < Copper done
clear
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question_answer 42)
The resistance of the fuse wire is:
A)
low done
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B)
moderate done
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C)
zero done
clear
D)
very high done
clear
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question_answer 43)
The temperature (T) dependence of resistivity \[(\rho )\] of a semiconductor is represented by:
A)
B)
C)
D)
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question_answer 44)
We use alloy for making of resistors, because they have
A)
B)
C)
D)
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question_answer 45)
The temperature coefficient of resistance of an alloy used for making resistors is:
A)
small and positive done
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B)
small and negative done
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C)
large and positive done
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D)
large and negative done
clear
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question_answer 46)
The resistance of a heating element is \[99\,\Omega \]at room temperature. What is the temperature of the element, if the resistance is found to be \[116\,\Omega \]? (Temperature coefficient of the material of the resistor is \[1.7\times {{10}^{-4}}{}^\circ {{C}^{-1}}\])
A)
\[999.9{}^\circ C\] done
clear
B)
\[1005.3{}^\circ C\] done
clear
C)
\[1020.2{}^\circ C\] done
clear
D)
\[1037.1{}^\circ C\] done
clear
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question_answer 47)
Identical piece of Ge and Cu are taken and cooled, then:
A)
resistivity of both increases done
clear
B)
resistivity of both decreases done
clear
C)
resistivity of Cu increases and Ge decreases done
clear
D)
resistivity of Cu decreases and Ge increases done
clear
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question_answer 48)
Which of the following is wrong? Resistivity of a conductor is:
A)
independent of temperature done
clear
B)
inversely proportional to temperature done
clear
C)
Independent of dimensions of conductor done
clear
D)
less than resistivity of a semiconductor done
clear
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question_answer 49)
A wire has a resistance of \[2.5\,\Omega \] at \[28{}^\circ C\] and a resistance of \[2.9\,\Omega \] at \[100{}^\circ C\]. The temperature coefficient of resistivity of material of the wire is:
A)
\[1.06\times {{10}^{-3}}{}^\circ {{C}^{-1}}\] done
clear
B)
\[3.5\times {{10}^{-2}}\,{}^\circ {{C}^{-1}}\] done
clear
C)
\[2.22\times {{10}^{-3}}\text{ }{}^\circ {{C}^{-1}}\] done
clear
D)
\[3.95\times {{10}^{-2}}\text{ }{}^\circ {{C}^{-1}}\] done
clear
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question_answer 50)
Joule's law of heating effect can be expressed as:
A)
\[H=\frac{{{V}^{2}}}{R}t\] done
clear
B)
\[H=\frac{{{l}^{2}}}{R}t\] done
clear
C)
\[H={{V}^{2}}Rt\] done
clear
D)
\[H=lRt\] done
clear
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question_answer 51)
A current of 2 A flows in a wire offering a resistance of \[10\,\Omega \]. Calculate the energy dissipated by the wire in 0.5 hours.
A)
72 Wh done
clear
B)
72 kJ done
clear
C)
7200 J done
clear
D)
72 kJh done
clear
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question_answer 52)
A bulb has a power of 200 W. What is the energy dissipated by it in 5 minutes?
A)
60 J done
clear
B)
1000 J done
clear
C)
60 kJ done
clear
D)
1 kJ done
clear
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question_answer 53)
A boy has two spare light bulbs in his drawer. One is marked 240 V and 100 W and the other is marked 240 V and 60 W. He tries to decide which of the following assertions are correct?
A)
The 60 W light bulb has more resistance and therefore burns less brightly done
clear
B)
The 60 W light bulb has less resistance and therefore burns less brightly done
clear
C)
The 100 W bulb has more resistance and therefore burns more brightly done
clear
D)
The 100 W bulb has less resistance and therefore bums less brightly done
clear
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question_answer 54)
Two resistors \[{{R}_{1}}\] and \[{{R}_{2}}\] of \[4\,\Omega \] and \[6\,\Omega \] are connected in parallel across a battery. The ratio of power dissipated in them, \[{{P}_{1}}:{{P}_{2}}\]will be: (CBSE 2020)
A)
4:9 done
clear
B)
3:2 done
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C)
9:4 done
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D)
2:3 done
clear
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question_answer 55)
Four wires of the same diameter are connected, in turn, between two points maintained at a constant potential difference. Their resistivities and lengths are; \[\rho \] and L (wire 1), \[1.2\text{ }\rho \] and 1.2 L (wire 2), \[0.9\text{ }\rho \] and 0.9 L (wire 3) and \[\rho \] and 1.5 L (wire 4). Rank the wires according to the rates at which energy is dissipated as heat, greatest first:
A)
4>3>1>2 done
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B)
4>2>1>3 done
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C)
1>2>3>4 done
clear
D)
3>1>2>4 done
clear
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question_answer 56)
A heater coil is rated 100 W, 200 V. It is cut into two identical parts. Both parts are connected together in parallel, to the same source of 200 V. The energy Liberated per second in the new combination is:
A)
100 J done
clear
B)
200 J done
clear
C)
300 J done
clear
D)
400J done
clear
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question_answer 57)
In the circuit shown in figure, heat developed across \[2\,\Omega ,\,\,4\,\Omega \]. and \[3\,\Omega \] resistances are in the ratio of:
A)
2 : 4 : 3 done
clear
B)
8 : 4 : 12 done
clear
C)
4 : 8 : 27 done
clear
D)
8 : 4 : 27 done
clear
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question_answer 58)
A cell of emf E is connected with an external resistance R, then potential difference across cell is V. The internal resistance of cell will be:
A)
\[\frac{(E-V)R}{E}\] done
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B)
\[\frac{(E-V)R}{V}\] done
clear
C)
\[\frac{(V-E)R}{V}\] done
clear
D)
\[\frac{(V-E)R}{E}\] done
clear
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question_answer 59)
About internal resistance of a cell, the correct statement is that it is:
A)
Constant for a given cell done
clear
B)
Infinite done
clear
C)
Finite and its value decreases with increase of time of use done
clear
D)
Finite and its value increases with increase of time of use done
clear
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question_answer 60)
A cell having an emf \[\varepsilon \] and internal resistance r is connected across a variable external resistance R. As the resistance R is increased, the plot of potential difference V across R is given by:
A)
B)
C)
D)
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question_answer 61)
A battery of emf 15 V and internal resistance of \[4\text{ }\Omega \] is connected to a resistor. If the current in the circuit is 2 A and the circuit is close(d) Resistance of the resistor and terminal voltage of the battery will be:
A)
\[2.5\,\Omega .\text{ }6\text{ }V\] done
clear
B)
\[3.5\text{ }\Omega ,\text{ }6\text{ }V\] done
clear
C)
\[2.5\text{ }\Omega ,\text{ }7\text{ }V\] done
clear
D)
\[3.5\text{ }\Omega \text{ }7\text{ }V\] done
clear
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question_answer 62)
Two batteries of emf \[{{\varepsilon }_{1}}\] and \[{{\varepsilon }_{2}}({{\varepsilon }_{2}}>{{\varepsilon }_{1}})\] and internal resistances \[{{r}_{1}}\] and \[{{r}_{2}}\] respectively are connected in parallel as shown in figure. (NCERT EXEMPLAR)
A)
The equivalent emf \[{{\varepsilon }_{eq}}\] of the two cells is between \[{{\varepsilon }_{1}}\] and \[{{\varepsilon }_{2}}\], i.e., \[{{\varepsilon }_{1}}<{{\varepsilon }_{eq}}<{{\varepsilon }_{2}}\] done
clear
B)
The equivalent emf \[{{\varepsilon }_{eq}}\] is smaller than \[{{\varepsilon }_{1}}\] done
clear
C)
The \[{{\varepsilon }_{eq}}\] is given by \[{{\varepsilon }_{eq}}={{\varepsilon }_{1}}+{{\varepsilon }_{2}}\] always done
clear
D)
\[{{\varepsilon }_{eq}}\] is independent of internal resistances \[{{r}_{1}}\] and \[{{r}_{2}}\] done
clear
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question_answer 63)
What is the internal resistance of a 2.1 V cell which gives a current of 0.2 A through a resistance of \[10\,\Omega \]?
A)
\[1\,\Omega \] done
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B)
\[0.5\,\Omega \] done
clear
C)
\[2\,\Omega \] done
clear
D)
\[3\,\Omega \] done
clear
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question_answer 64)
A cell of emf E and internal resistance r is connected across a resistance R. If internal resistance is equal to R, then the potential difference between the terminals of the cell must be:
A)
E done
clear
B)
\[\frac{E}{2}\] done
clear
C)
\[\frac{E}{4}\] done
clear
D)
\[\frac{3E}{2}\] done
clear
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question_answer 65)
Two batteries of emfs 2 V and 1 V of internal resistances \[1\,\Omega \] and \[2\,\Omega \] respectively are connected in parallel. The effective emf of the combination is:
A)
\[\frac{3}{2}V\] done
clear
B)
\[\frac{5}{3}V\] done
clear
C)
\[\frac{3}{5}V\] done
clear
D)
\[2\,V\] done
clear
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question_answer 66)
Current provided by a battery is maximum when
A)
internal resistance is equal to external resistance done
clear
B)
internal resistance is greater than external resistance done
clear
C)
internal resistance is less than external resistance done
clear
D)
None of the above done
clear
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question_answer 67)
A cell supplies a current of 0.9 A through a \[2\,\Omega \]resistor and a current of 0.3 A through \[7\,\Omega \] resistor. The internal resistance of the cell is:
A)
\[2.0\,\Omega \] done
clear
B)
\[1.5\,\Omega \] done
clear
C)
\[1.0\,\Omega \] done
clear
D)
\[0.5\,\Omega \] done
clear
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question_answer 68)
The battery of a trunk has an emf of 24 V. If the internal resistance of the battery is \[0.8\text{ }\Omega \]. What is the maximum current that can be drawn from the battery?
A)
30 A done
clear
B)
32 A done
clear
C)
33 A done
clear
D)
34 A done
clear
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question_answer 69)
A battery having 12 V emf and internal resistance \[3\,\Omega \] is connected to a resistor. If the current in the circuit is 1 A, then the resistance of resistor and lost voltage of the battery when circuit is closed will be:
A)
\[7\text{ }\Omega \text{, }7\text{ }V\] done
clear
B)
\[8\text{ }\Omega ,\,8\text{ }V\] done
clear
C)
\[9\text{ }\Omega ,\text{ }9\text{ }V\] done
clear
D)
\[9\text{ }\Omega ,10\text{ }V\] done
clear
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question_answer 70)
Five cells each of emf E and resistance r are connected in series. Due to oversight one cell is connected wrongly. The equivalent emf and internal resistance of the combination is:
A)
5E done
clear
B)
2E done
clear
C)
3E done
clear
D)
4E done
clear
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question_answer 71)
Three identical cells, each of 4V and internal resistance r, are connected in series to a \[6\,\Omega \] resistor. If the current flowing in the circuit is 2 (A) The internal resistance of each cell is:
A)
\[0.11\,\Omega \] done
clear
B)
\[0.\,\Omega \] done
clear
C)
\[0.12\,\Omega \] done
clear
D)
\[1.1\,\Omega \] done
clear
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question_answer 72)
In the electric circuit shown, each cell has an emf of 2 V and internal resistance is \[1\,\Omega \]. The external resistance is \[2\,\Omega \]. The value of the current l is (in ampere):
A)
2 done
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B)
1.25 done
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C)
0.4 done
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D)
1.2 done
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question_answer 73)
If n identical cells of emf \[\varepsilon \]. and internal resistance r are connected in series, then the total emf and equivalent internal resistance of the combination will be:
A)
\[\varepsilon \frac{r}{n}\] done
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B)
\[\varepsilon ,\,nr\] done
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C)
\[n\varepsilon ,\,\frac{r}{n}\] done
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D)
\[n\varepsilon ,\,nr\] done
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question_answer 74)
If n cells each of emf \[\varepsilon \] and internal resistance r are connected in parallel, then the total emf and internal resistances will be:
A)
\[\varepsilon ,\frac{r}{n}\] done
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B)
\[\varepsilon ,nr\] done
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C)
\[n\varepsilon ,\frac{r}{n}\] done
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D)
\[n\varepsilon ,nr\] done
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question_answer 75)
The basic laws for analyzing an electric circuit are:
A)
Einstein's theory done
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B)
Newton's laws done
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C)
Kirchhoff's laws done
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D)
Faraday's laws done
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question_answer 76)
Kirchhoff's first and second laws are respectively based on law of conservation of:
A)
momentum and energy done
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B)
charge and energy done
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C)
mass and energy done
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D)
None of the above done
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question_answer 77)
The value of current l in figure is:
A)
4 A done
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B)
6 A done
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C)
3 A done
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D)
5 A done
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question_answer 78)
Figure shows currents in a part of an electric circuit, then current l is:
A)
1.7 A done
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B)
3.7 A done
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C)
1.3 A done
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D)
1 A done
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question_answer 79)
In the given circuit the potential at point B is zero, the potential at points A and D will be:
A)
\[{{V}_{A}}=4\,V;{{V}_{D}}=9\,V\] done
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B)
\[{{V}_{A}}=3\,V;{{V}_{D}}=4\,V\] done
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C)
\[{{V}_{A}}=9\,V;{{V}_{D}}=3\,V\] done
clear
D)
\[{{V}_{A}}=4\,V;{{V}_{D}}=3\,V\] done
clear
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question_answer 80)
In the circuit diagram, calculate the electric current through branch BC:
A)
4 A done
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B)
2 A done
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C)
5 A done
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D)
10 A done
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question_answer 81)
Electric current through resistance \[10\text{ }\Omega \], in the given circuit is:
A)
0 A done
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B)
0.5 A done
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C)
6/11A done
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D)
2A done
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question_answer 82)
A 7 V battery with internal resistance \[2\,\Omega \] and a 3 V battery with internal resistance \[1\,\Omega \] are connected to a \[10\,\Omega \] resistor as shown in figure, the current in \[10\,\Omega \] resistor is:
A)
0.27 A done
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B)
0.31 A done
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C)
0.031 A done
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D)
0.53 A done
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question_answer 83)
In a balanced Wheatstone's network, the resistances in arms Q and S are interchange(d) As a result of this:
A)
galvanometer and the cell must be interchanged to balance done
clear
B)
galvanometer shows zero deflection done
clear
C)
network is not balanced done
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D)
network is still balanced done
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question_answer 84)
Wheatstone bridge works on the principle of..........
A)
full deflection done
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B)
partial deflection done
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C)
no deflection done
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D)
null deflection done
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question_answer 85)
WSB experiment is most sensitive, when:
A)
all four resistance are approximately equal done
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B)
one of the resistance is very high as compare to others done
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C)
one of the resistance is very low as compare to others done
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D)
any two resistances are equal to infinity done
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question_answer 86)
In a Wheatstone's bridge, all the four arms have equal resistance R. If resistance of the galvanometer arm is also R, then equivalent resistance of the combination is:
A)
R done
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B)
2R done
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C)
\[\frac{R}{2}\] done
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D)
\[\frac{R}{4}\] done
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question_answer 87)
In a Wheatstone bridge if the battery and galvanometer are interchanged, then the deflection in galvanometer will:
A)
change in previous direction done
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B)
not change done
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C)
change in opposite direction done
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D)
None of the above done
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question_answer 88)
Determine the electric current through branch BD of the electric network:
A)
0.6 A done
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B)
0 A done
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C)
1 A done
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D)
10 A done
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question_answer 89)
Four resistances of \[3\,\Omega ,\,3\,\Omega ,\,3\,\Omega \] and \[4\,\Omega \] respectively are used to a form of a Wheatstone bridge. The \[4\,\Omega \] resistance is short circuited with a resistance R in order to get bridge balanced. The value of R will be:
A)
\[10\,\Omega \] done
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B)
\[11\,\Omega \] done
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C)
\[12\,\Omega \] done
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D)
\[13\,\Omega \] done
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question_answer 90)
Four resistors are connected as shown in the figure. A 6 V battery of negligible resistance is connected across terminals A and C. The potential difference across terminals B and D will be:
A)
Zero done
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B)
1.5 V done
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C)
2 V done
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D)
3 V done
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question_answer 91)
Consider the following statements regarding the network shown in the figure: 1. The equivalent resistance of the network between points A and B is \[\left( \frac{4}{3}R \right)\]. 2. The current in resistor 3R is zero. 3. The potential difference across R is equal to the potential difference across 2R. Which of the above statement(s) is/are correct?
A)
1 only done
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B)
2 only done
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C)
2 and 3 done
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D)
1, 2 and 3 done
clear
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question_answer 92)
Meter bridge is application of:
A)
Kirchhoff's current law done
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B)
Kirchhoff's voltage law done
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C)
balance Wheatstone bridge done
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D)
Both (a) and b, done
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question_answer 93)
The resistances in left and right gap of a meter bridge are \[20\,\Omega \] and \[30\,\Omega \] respectively. When the resistance in the left gap is reduced to half its value, the balance point shifts by:
A)
15 cm to the right done
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B)
15 cm to the left done
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C)
20 cm to the right done
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D)
20 cm to the left done
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question_answer 94)
A resistance R is to be measured using a meter bridge. Student chooses the standard resistance S to be \[100\text{ }\Omega \]. He finds the null point at \[{{l}_{1}}=2.9\,cm\]. He is told to attempt to improve the accuracy. Which of the following is a useful Way? (NCERT EXEMPLAR)
A)
He should measure \[{{l}_{1}}\] more accurately done
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B)
He should change S to \[1000\text{ }\Omega \]and repeat the experiment done
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C)
He should change S to \[\text{3 }\Omega \] and repeat the experiment done
clear
D)
He should give up hope of a more accurate measurement with a meter bridge done
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question_answer 95)
In a meter bridge experiment, the ratio of the left gap resistance to right gap resistance is 2 : 3, the balance point from left is:
A)
60 cm done
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B)
50 cm done
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C)
40 cm done
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D)
20 cm done
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question_answer 96)
In a metre bridge experiment, resistance box (with \[R=2\text{ }\Omega \]) is connected in the left gap and the unknown resistance S in the right gap. If balancing length be 40 cm, calculate value of S.
A)
\[\text{2 }\Omega \] done
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B)
\[\text{3 }\Omega \] done
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C)
\[\text{4 }\Omega \] done
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D)
\[\text{2}\text{.5 }\Omega \] done
clear
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question_answer 97)
What is the value of unknown resistance R, if galvanometer shows null deflection in the given meter bridge set up?
A)
\[97.5\text{ }\Omega \] done
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B)
\[105\text{ }\Omega \] done
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C)
\[150\text{ }\Omega \] done
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D)
\[110\text{ }\Omega \] done
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question_answer 98)
A potentiometer can measure emf of a cell because: (CBSE 2020)
A)
the sensitivity of potentiometer is large done
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B)
no current is drawn from the cell at balance done
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C)
no current flows in the wire of potentiometer at balance done
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D)
internal resistance of cell is neglected done
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question_answer 99)
For measurement of potential difference, a potentiometer is preferred over voltmeter because:
A)
potentiometer is more sensitive than voltmeter done
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B)
the resistance of potentiometer is less than voltmeter done
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C)
potentiometer is cheaper than voltmeter done
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D)
potentiometer does not take current from the circuit done
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question_answer 100)
With a certain cell, the balance point is obtained at 65 cm from the end of a potentiometer wire. With another cell whose emf differs from that of the first by 0.1 V, the balance point is obtained at 60 cm. Then the emf of each cell is:
A)
1.2 V and 1.5 V respectively done
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B)
2.1 V and 2.2 V respectively done
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C)
1.3 V and 1.2 V respectively done
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D)
5.1 V and 5.2 V respectively done
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question_answer 101)
Two cells of emfs approximately 5 V and 10 V are to be accurately compared using a potentiometer of length 400cm. (NCERT EXEMPLAR)
A)
The battery that runs the potentiometer should have voltage of 8 V done
clear
B)
The battery of potentiometer can have a voltage of 15 V and R adjusted so that the potential drop across the wire slightly exceeds 10V done
clear
C)
The first portion of 50 cm of wire itself should have potential drop of 10 V done
clear
D)
Potentiometer is usually used for comparing resistances and not voltages done
clear
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question_answer 102)
AB is a wire of potentiometer with the increase in the value of resistance R, the shift in the balance point J will be:
A)
towards B done
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B)
towards A done
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C)
remains constant done
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D)
first towards B, then back towards A done
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question_answer 103)
In a potentiometer a cell of emf 1.5 V gives a balanced point at 32 cm length of the wire. If the cell is replaced by another cell, then the balance point shifts to 65.0 cm, then the emf of second cell is:
A)
3.05 V done
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B)
2.05 V done
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C)
4.05 V done
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D)
6.05 V done
clear
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question_answer 104)
For a cell of emf 2 V, a balance is obtained for 50 cm of the potentiometer wire. If the cell is shunted by a \[2\,\Omega \] resistor and the balance is obtained across 40 cm of the wire, then the internal resistance of the cell is:
A)
\[1\,\Omega \] done
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B)
\[0.5\,\Omega \] done
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C)
\[1.2\,\Omega \] done
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D)
\[2.5\,\Omega \] done
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question_answer 105)
In a potentiometer the balancing with a cell is at length of 220 cm. On shunting the cell with a resistance of \[3\,\Omega \] balance length becomes 130 cm. What is the internal resistance of this cell?
A)
\[4.5\,\Omega \] done
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B)
\[7.8\,\Omega \] done
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C)
\[6.3\,\Omega \] done
clear
D)
\[2.08\,\Omega \] done
clear
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