-
question_answer1)
The phenomenon of ejection of electrons from the surface of metal, when light of a suitable frequency falls on it, is called
A)
electrolysis done
clear
B)
ionization done
clear
C)
photoelectric effect done
clear
D)
none of these done
clear
View Solution play_arrow
-
question_answer2)
The photoelectric effect is described as the ejection of electrons from the surface of a metal when
A)
it is heated to a high temperature done
clear
B)
light of suitable frequency falls on it done
clear
C)
electrons of suitable velocity impinge on it done
clear
D)
it is placed in a strong magnetic field done
clear
View Solution play_arrow
-
question_answer3)
Photoelectric effect was discovered by
A)
hertz done
clear
B)
Wallach done
clear
C)
Lenard done
clear
D)
Millikan done
clear
View Solution play_arrow
-
question_answer4)
A steam engine converts the heat energy of steam into
A)
electrical energy done
clear
B)
nuclear energy done
clear
C)
mechanical energy done
clear
D)
none of these done
clear
View Solution play_arrow
-
question_answer5)
A motor converts electrical energy into
A)
mechanical energy done
clear
B)
chemical energy done
clear
C)
nuclear energy done
clear
D)
thermal energy done
clear
View Solution play_arrow
-
question_answer6)
A battery converts chemical energy into
A)
mechanical energy done
clear
B)
solar energy done
clear
C)
electrical energy done
clear
D)
none of these done
clear
View Solution play_arrow
-
question_answer7)
Ratio of the SI units to CGS units of energy is
A)
105 done
clear
B)
106 done
clear
C)
107 done
clear
D)
10.7 done
clear
View Solution play_arrow
-
question_answer8)
Energy possessed by a body due to its motion is
A)
kinetic energy done
clear
B)
nuclear energy done
clear
C)
potential energy done
clear
D)
thermal energy done
clear
View Solution play_arrow
-
question_answer9)
Energy possessed by a body due to its configuration is
A)
kinetic energy done
clear
B)
nuclear energy done
clear
C)
potential energy done
clear
D)
thermal energy done
clear
View Solution play_arrow
-
question_answer10)
One erg is equal to
A)
\[\text{1 g cm }{{\text{s}}^{-\text{2}}}\] done
clear
B)
1 Nm done
clear
C)
\[{{10}^{7}}\,\,J\] done
clear
D)
\[{{10}^{-7}}\,\,J\] done
clear
View Solution play_arrow
-
question_answer11)
The phenomenon of photoelectric effect was explained by
A)
Wallach done
clear
B)
Einstein done
clear
C)
Planck done
clear
D)
Bohr done
clear
View Solution play_arrow
-
question_answer12)
A photoelectric cell converts
A)
light energy into electrical energy done
clear
B)
light energy into sound energy done
clear
C)
electric energy into light energy done
clear
D)
light energy into heat energy done
clear
View Solution play_arrow
-
question_answer13)
It is essential to consider light as a stream of photons to explain
A)
rectilinear propagation of light done
clear
B)
photoelectric effect done
clear
C)
refraction of light done
clear
D)
diffraction of light done
clear
View Solution play_arrow
-
question_answer14)
The photoelectric effect can be understood on the basis of
A)
wave theory of light only done
clear
B)
quantum theory of light only done
clear
C)
electromagnetic theory of light only done
clear
D)
none of these done
clear
View Solution play_arrow
-
question_answer15)
Which one of the following is different from the others?
A)
Joule done
clear
B)
Kilowatt hour done
clear
C)
Erg done
clear
D)
Watt done
clear
View Solution play_arrow
-
question_answer16)
If the product of muscle and speed equals power, then the muscle stand for
A)
force done
clear
B)
power done
clear
C)
energy done
clear
D)
momentum done
clear
View Solution play_arrow
-
question_answer17)
Which of the following can't be used to make a solar cell?
A)
Silicon done
clear
B)
Platinum done
clear
C)
Gallium done
clear
D)
Germanium done
clear
View Solution play_arrow
-
question_answer18)
With the addition of impurities, the resistance of a semi-conductor
A)
increases done
clear
B)
decreases done
clear
C)
first decreases then increases done
clear
D)
first increases then decreases done
clear
View Solution play_arrow
-
question_answer19)
A photon is a/an
A)
quantum of light energy done
clear
B)
quantum of matter done
clear
C)
positively charged particle done
clear
D)
instrument for measuring light intensity done
clear
View Solution play_arrow
-
question_answer20)
A photon of frequency v has an energy
A)
\[\frac{h}{v}\] done
clear
B)
\[\frac{v}{h}\] done
clear
C)
\[v\] done
clear
D)
\[hv\] done
clear
View Solution play_arrow
-
question_answer21)
Units of Planck's constant in CGS system are:
A)
erg per second done
clear
B)
second per erg done
clear
C)
erg second done
clear
D)
erg per second per second done
clear
View Solution play_arrow
-
question_answer22)
Planck's constant has the dimensions of
A)
energy done
clear
B)
mass done
clear
C)
frequency done
clear
D)
angular momentum done
clear
View Solution play_arrow
-
question_answer23)
Of the following, the biggest unit of energy is
A)
Joule done
clear
B)
Kilowatt hour done
clear
C)
Erg done
clear
D)
Electron volt done
clear
View Solution play_arrow
-
question_answer24)
Of the following converts light energy into electrical energy?
A)
motor done
clear
B)
battery done
clear
C)
solar cell done
clear
D)
None of these done
clear
View Solution play_arrow
-
question_answer25)
If speed of a motor car becomes six times, then the kinetic energy becomes
A)
6 times done
clear
B)
36 times done
clear
C)
12 times done
clear
D)
24 times done
clear
View Solution play_arrow
-
question_answer26)
Spring of the winding knob of a watch has
A)
mechanical energy done
clear
B)
only kinetic energy done
clear
C)
only potential energy done
clear
D)
kinetic or potential energy done
clear
View Solution play_arrow
-
question_answer27)
A body is moved through a distance of 5 m in the following different ways. Maximum work is done when the body is
A)
pushed over an inclined plane done
clear
B)
raised vertically upwards done
clear
C)
pushed over smooth rollers done
clear
D)
pushed on a plane horizontal surface done
clear
View Solution play_arrow
-
question_answer28)
Rest mass of a photon is
A)
\[\frac{h\upsilon }{{{c}^{2}}}\] done
clear
B)
\[\frac{h\upsilon }{c}\] done
clear
C)
\[h\upsilon \] done
clear
D)
zero done
clear
View Solution play_arrow
-
question_answer29)
Mass of a moving photon is
A)
\[\frac{h\upsilon }{{{c}^{2}}}\] done
clear
B)
\[\frac{h\upsilon }{c}\] done
clear
C)
\[h\upsilon \] done
clear
D)
zero done
clear
View Solution play_arrow
-
question_answer30)
A photon of frequency v has a momentum associated with it. If c is the velocity of light, then momentum is
A)
\[\frac{hv}{{{c}^{2}}}\] done
clear
B)
\[\frac{hv}{c}\] done
clear
C)
\[\frac{v}{c}\] done
clear
D)
\[h\,v\,c\] done
clear
View Solution play_arrow
-
question_answer31)
The momentum of a photon having energy E is
A)
\[\frac{E}{c}\] done
clear
B)
\[\frac{E}{{{c}^{2}}}\] done
clear
C)
\[\frac{E}{h}\] done
clear
D)
zero done
clear
View Solution play_arrow
-
question_answer32)
The work function of a metal is W and the frequency of incident light is d. There is no emission of photoelectrons when
A)
\[v<\frac{W}{h}\] done
clear
B)
\[v=\frac{W}{h}\] done
clear
C)
\[v>\frac{W}{h}\] done
clear
D)
\[v\ge \frac{W}{h}\] done
clear
View Solution play_arrow
-
question_answer33)
In the above problem, minimum work is done when the body is
A)
pushed over an inclined plane done
clear
B)
raised vertically upwards done
clear
C)
pushed over smooth rollers done
clear
D)
pushed on a plane horizontal surface done
clear
View Solution play_arrow
-
question_answer34)
A truck and a car are moving on a smooth, level road such that the kinetic energy associated with them is same. Brakes are applied simultaneously in both of them such that equal retarding forces are produced in them. Which one will cover a greater distance before it stops?
A)
Car done
clear
B)
Truck done
clear
C)
Both will cover the same distance done
clear
D)
Nothing can be decided done
clear
View Solution play_arrow
-
question_answer35)
The unit kg \[{{m}^{2}}{{s}^{-2}}\] is associated with
A)
work done
clear
B)
kinetic energy done
clear
C)
potential energy done
clear
D)
All of these done
clear
View Solution play_arrow
-
question_answer36)
Work function is the energy required to
A)
producer-rays done
clear
B)
excite an atom done
clear
C)
explore an atom done
clear
D)
eject an electron just out of the surface done
clear
View Solution play_arrow
-
question_answer37)
Photoelectric effect can be explained only by assuming that light
A)
is a form of transverse waves done
clear
B)
is a form of longitudinal waves done
clear
C)
can be polarized done
clear
D)
consists of quanta done
clear
View Solution play_arrow
-
question_answer38)
In photoelectric effect, the photo current
A)
increases with increase of frequency of incident photon done
clear
B)
decreases with increase of frequency of incident photon done
clear
C)
does not depend on the frequency of photon but depends only on the intensity of incident light done
clear
D)
depends both on intensity and frequency of the incident photon done
clear
View Solution play_arrow
-
question_answer39)
Kinetic energy of a body is increased most by doubling its
A)
mass done
clear
B)
density done
clear
C)
weight done
clear
D)
speed done
clear
View Solution play_arrow
-
question_answer40)
A body is dropped from a certain height to the ground. When it is halfway down, then it possesses
A)
only kinetic energy done
clear
B)
only potential energy done
clear
C)
both kinetic energy and potential energy done
clear
D)
neither kinetic energy nor potential energy done
clear
View Solution play_arrow
-
question_answer41)
Usha lifts a doll from the floor and places it on a table. If the weight of the doll is known, what else does one need to know in order to calculate the work Asha has done on the doll?
A)
Time required done
clear
B)
Height of the table done
clear
C)
Mass of the doll done
clear
D)
Cost of the doll done
clear
View Solution play_arrow
-
question_answer42)
A source of light is placed at a distance 1 m from a photocell and cut off potential is found to be \[{{V}_{0}}\] If the distance is doubled, then cut-off potential will be
A)
\[\text{2}{{\text{V}}_{0}}\] done
clear
B)
\[{{\text{V}}_{0}}/\text{2}\] done
clear
C)
\[{{\text{V}}_{0}}\] done
clear
D)
\[{{\text{V}}_{0}}/\text{2}\] done
clear
View Solution play_arrow
-
question_answer43)
Of the following, the fuel different from other is
A)
charcoal done
clear
B)
lignite done
clear
C)
coke done
clear
D)
alcohol done
clear
View Solution play_arrow
-
question_answer44)
In photoelectric effect, the number photoelectrons emitted is proportional to
A)
intensity of incident beam done
clear
B)
frequency of incident beam done
clear
C)
velocity of incident beam done
clear
D)
work function of photo cathode done
clear
View Solution play_arrow
-
question_answer45)
The photoelectric threshold of a certain metal is \[\text{3}000\,\overset{\text{o}}{\mathop{\text{A}}}\,\] . If the radiation of\[\text{2}000\,\overset{\text{o}}{\mathop{\text{A}}}\,\] is incident on the metal, then
A)
electrons will be emitted done
clear
B)
positrons will be emitted done
clear
C)
protons will be emitted done
clear
D)
electrons will not be emitted done
clear
View Solution play_arrow
-
question_answer46)
Which of the following statements is correct?
A)
current in a photocell increases with increasing frequency of light done
clear
B)
photocurrent is proportional to applied voltage done
clear
C)
photocurrent increases with increasing intensity of light done
clear
D)
stopping potential increases with increasing intensity of incident light done
clear
View Solution play_arrow
-
question_answer47)
If two bodies of equal weights are kept at heights h and 1.5 h respectively, then the ratio of their potential energies is
A)
3 : 2 done
clear
B)
1 : 1 done
clear
C)
2 : 3 done
clear
D)
3 : 4 done
clear
View Solution play_arrow
-
question_answer48)
The acceleration due to gravity on the moon is One - sixth that on the earth. If a high jumper can jump 2 m on earth, then what distance can he jump on the moon?
A)
2m done
clear
B)
12m done
clear
C)
6m done
clear
D)
8m done
clear
View Solution play_arrow
-
question_answer49)
Solar energy can be used to produce
A)
electrical energy done
clear
B)
mechanical energy done
clear
C)
heat energy done
clear
D)
All of these done
clear
View Solution play_arrow
-
question_answer50)
Which of the following devices transforms light energy into chemical energy?
A)
Car dynamo done
clear
B)
Electric motor done
clear
C)
Electric fan done
clear
D)
None of these done
clear
View Solution play_arrow
-
question_answer51)
If momentum of a body increases by 20%, then the percentage increase in its kinetic energy is
A)
36 done
clear
B)
44 done
clear
C)
52 done
clear
D)
60 done
clear
View Solution play_arrow
-
question_answer52)
Energy of the electric current is
A)
thermal done
clear
B)
nuclear done
clear
C)
electrical done
clear
D)
chemical done
clear
View Solution play_arrow
-
question_answer53)
Variation of photoelectric current given by the photocell with the intensity of light is given by a graph, which is
A)
a parabola done
clear
B)
a straight line with positive slope with intercept on current axis done
clear
C)
a straight line with positive slope with intercept on current axis done
clear
D)
a straight line with negative slope done
clear
View Solution play_arrow
-
question_answer54)
Energy of a photon of light of wavelength 450 Nm is
A)
\[\text{4}.\text{4 }\times \text{ 1}{{0}^{-\text{19}}}J\] done
clear
B)
\[\text{2}.\text{5 }\times \text{ 1}{{0}^{-\text{19}}}\text{ J}\] done
clear
C)
\[\text{1}.\text{25 }\times \text{ 1}{{0}^{-\text{17}}}\text{ J}\] done
clear
D)
\[\text{2}.\text{5 }\times \text{ 1}{{0}^{-\text{17}}}\text{ J}\] done
clear
View Solution play_arrow
-
question_answer55)
Frequency of a photon having energy \[66\,\,\,eV\] is
A)
\[\text{8 }\times \text{ 1}{{0}^{-\text{15}}}\text{ Hz}\] done
clear
B)
\[\text{12 }\times \text{ 1}{{0}^{-\text{15}}}\text{ Hz}\] done
clear
C)
\[\text{16 }\times \text{ 1}{{0}^{\text{15}}}\text{ Hz}\] done
clear
D)
None of these done
clear
View Solution play_arrow
-
question_answer56)
If momentum of a photon of an electromagnetic radiation is\[\text{3}.\text{3 }\times \text{ 1}{{0}^{-\text{29}}}\text{ kg m}/\text{sec}\], then frequency of associated wave is
A)
\[\text{3}.0\times \text{1}{{0}^{3}}\text{ Hz}\] done
clear
B)
\[6.0\times \text{l}{{0}^{\text{3}}}\text{Hz}\] done
clear
C)
\[\text{7}.\text{5 }\times \text{ 1}{{0}^{\text{5}}}\text{ Hz}\] done
clear
D)
\[\text{1}.\text{5 }\times \text{ 1}{{0}^{\text{13}}}\text{ Hz}\] done
clear
View Solution play_arrow
-
question_answer57)
Energy possessed by the wind is
A)
kinetic energy done
clear
B)
potential energy done
clear
C)
thermal energy done
clear
D)
sound energy done
clear
View Solution play_arrow
-
question_answer58)
Hydro-electric power generates
A)
electrical energy done
clear
B)
nuclear energy done
clear
C)
thermal energy done
clear
D)
None of these done
clear
View Solution play_arrow
-
question_answer59)
he steam engine was invented by
A)
James Watt done
clear
B)
Joule done
clear
C)
New common done
clear
D)
Newton done
clear
View Solution play_arrow
-
question_answer60)
The fuel used in a steam engine is
A)
water done
clear
B)
carbon dioxide done
clear
C)
carbon monoxide done
clear
D)
none of these done
clear
View Solution play_arrow
-
question_answer61)
The petrol engine was invented by
A)
Nikolaus Otto done
clear
B)
James Watt done
clear
C)
Rudolph Diesel done
clear
D)
None of these done
clear
View Solution play_arrow
-
question_answer62)
Momentum of a photon having frequency \[\text{1}.\text{5 }\times \text{ 1}{{0}^{\text{13}}}\text{ Hz}\]?
A)
\[\text{3}.\text{3 }\times \text{ 1}{{0}^{-\text{29}}}\text{ kg m}/\text{s}\] done
clear
B)
\[\text{3}.\text{3 }\times \text{ 1}{{0}^{-\text{34}}}\text{ kg m}/\text{s}\] done
clear
C)
\[\text{6}.\text{6 }\times \text{ 1}{{0}^{-\text{34}}}\text{ kg m}/\text{s}\] done
clear
D)
\[\text{6}.\text{6 }\times \text{ 1}{{0}^{-\text{3}0}}\text{ kg m}/\text{s}\] done
clear
View Solution play_arrow
-
question_answer63)
Einstein's photoelectric equation is
A)
\[h\upsilon =\frac{{{W}_{0}}}{2}-m{{\upsilon }^{2}}\] done
clear
B)
\[h\upsilon ={{W}_{0}}\frac{1}{2}m{{\upsilon }^{2}}\] done
clear
C)
\[h\upsilon ={{W}_{0}}+\frac{1}{2}m{{\upsilon }^{2}}\] done
clear
D)
\[h\upsilon =\frac{1}{2}m{{\upsilon }^{2}}-{{W}_{0}}\] done
clear
View Solution play_arrow
-
question_answer64)
Joule's experiment converts
A)
work into heat done
clear
B)
work into electricity done
clear
C)
heat into work done
clear
D)
electricity into work done
clear
View Solution play_arrow
-
question_answer65)
One watt hour equals
A)
3600 J done
clear
B)
360 J done
clear
C)
36 J done
clear
D)
3.6 J done
clear
View Solution play_arrow
-
question_answer66)
Of the following, the fuel having different from others is
A)
water gas done
clear
B)
coal gas done
clear
C)
producer gas done
clear
D)
coke done
clear
View Solution play_arrow
-
question_answer67)
Of the following, the fuel different from others is
A)
Diesel done
clear
B)
Gasoline done
clear
C)
Alcohol done
clear
D)
Lignite done
clear
View Solution play_arrow
-
question_answer68)
A solar cell converts heat and light energy into
A)
heat energy done
clear
B)
sound energy done
clear
C)
electricity done
clear
D)
nuclear energy done
clear
View Solution play_arrow
-
question_answer69)
One mega joule approximately equals
A)
240 kcal done
clear
B)
2400 kcal done
clear
C)
24 kcal done
clear
D)
2.4 kcal done
clear
View Solution play_arrow
-
question_answer70)
Of the following, the fuel having least calorific value is
A)
Petrol done
clear
B)
Kerosene done
clear
C)
Diesel done
clear
D)
Coke done
clear
View Solution play_arrow
-
question_answer71)
The photoelectric work function
A)
is different for different metals done
clear
B)
is same for all metals done
clear
C)
depends upon frequency of incident light done
clear
D)
depends upon intensity of incident light done
clear
View Solution play_arrow
-
question_answer72)
The current in a photoelectric tube
A)
decreases with increase in frequency of the incident photon done
clear
B)
increases with increase in frequency of the incident photon done
clear
C)
decreases with increases in intensity of illumination done
clear
D)
increases with increase in intensity of illumination done
clear
View Solution play_arrow
-
question_answer73)
A metallic surface ejects photoelectrons when hit by green light but none when hit by yellow light. Will the electrons be ejected if the same surface is hit by red light?
A)
yes done
clear
B)
yes, if the red beam is sufficiently intense done
clear
C)
can?t say done
clear
D)
none of these done
clear
View Solution play_arrow
-
question_answer74)
Heat flows as a result of difference in
A)
masses done
clear
B)
weights done
clear
C)
temperatures done
clear
D)
none of these done
clear
View Solution play_arrow
-
question_answer75)
Temperature of water at the bottom of a waterfall is higher than that of the water at the top, because
A)
falling water absorbs heat from the sun done
clear
B)
kinetic energy of the falling water is converted into heat done
clear
C)
water at the bottom has greater potential energy done
clear
D)
the rocks on the river bed give out heat done
clear
View Solution play_arrow
-
question_answer76)
Work done can be converted from joules to calories by
A)
dividing by \[J\] done
clear
B)
subtracting \[J\] done
clear
C)
multiplying by \[J\] done
clear
D)
adding \[J\] where,\[J\]= mechanical equivalent of heat. done
clear
View Solution play_arrow
-
question_answer77)
A car engine is an example of
A)
internal combustion engine done
clear
B)
external combustion engine done
clear
C)
neither internal nor external combustion engine done
clear
D)
both internal and external combustion engines done
clear
View Solution play_arrow
-
question_answer78)
Cathode rays are
A)
a stream of electrons done
clear
B)
a stream of positive ions done
clear
C)
a stream of uncharged particles done
clear
D)
same as canal rays done
clear
View Solution play_arrow
-
question_answer79)
If cathode rays enter a magnetic field making an oblique angle with lines of induction, then their path in the magnetic field is
A)
A straight line done
clear
B)
Helix done
clear
C)
A circle done
clear
D)
Parabola done
clear
View Solution play_arrow
-
question_answer80)
The specific charge for cathode rays is
A)
constant done
clear
B)
variable done
clear
C)
dependent upon the material of the cathode done
clear
D)
dependent upon the nature of gas in the discharge tube done
clear
View Solution play_arrow
-
question_answer81)
The practical unit for the measurement of electric power is
A)
watt done
clear
B)
kilowatt done
clear
C)
kilowatt hour done
clear
D)
horse power done
clear
View Solution play_arrow
-
question_answer82)
Wood is a
A)
primary fuel done
clear
B)
liquid fuel done
clear
C)
processed fuel done
clear
D)
secondary fuel done
clear
View Solution play_arrow
-
question_answer83)
An example of secondary fuel is
A)
coal done
clear
B)
water gas done
clear
C)
natural gas done
clear
D)
petroleum done
clear
View Solution play_arrow
-
question_answer84)
Which of the following is an example of fossil fuel?
A)
Coal gas done
clear
B)
Coke done
clear
C)
Natural gas done
clear
D)
Producer gas done
clear
View Solution play_arrow
-
question_answer85)
Most of the fuels are
A)
carbon compounds with sulphur done
clear
B)
nitrogen compounds with carbon done
clear
C)
carbon compounds with hydrogen done
clear
D)
None of these done
clear
View Solution play_arrow
-
question_answer86)
Cathode rays rain K. E. when they are accelerated by an electric field. If cathode rays are subjected to the action of magnetic field, then their
A)
energy increases done
clear
B)
momentum increases done
clear
C)
potential energy increases done
clear
D)
energy and momentum remain unaffected done
clear
View Solution play_arrow
-
question_answer87)
The force experienced by an electron with constant velocity parallel to the direction o1 uniform magnetic field B is
A)
\[eVB\] done
clear
B)
\[\frac{eV}{B}\] done
clear
C)
\[eB\] done
clear
D)
Zero done
clear
View Solution play_arrow
-
question_answer88)
Destructive distillation of coal leads to the formation of
A)
wood done
clear
B)
kerosene done
clear
C)
ammonia Cal liquor done
clear
D)
charcoal done
clear
View Solution play_arrow
-
question_answer89)
When steam is passed over hot coke, it produces
A)
producer gas done
clear
B)
water gas done
clear
C)
laughing gas done
clear
D)
coal gas done
clear
View Solution play_arrow
-
question_answer90)
Producer gas is a mixture of
A)
carbon monoxide and nitrogen gas done
clear
B)
carbon monoxide and hydrogen gas done
clear
C)
carbon monoxide and water vapour done
clear
D)
carbon monoxide and nitrous oxide done
clear
View Solution play_arrow
-
question_answer91)
The fractional distillation of coaltar yields
A)
carbon disulphide done
clear
B)
kerosene oil done
clear
C)
carbon tetrachloride done
clear
D)
benzene done
clear
View Solution play_arrow
-
question_answer92)
Which of the following is not obtained on fractional distillation of petroleum?
A)
Paraffin wax done
clear
B)
Asphalt done
clear
C)
Coal gas done
clear
D)
Petroleum gas done
clear
View Solution play_arrow
-
question_answer93)
Cathode ray oscillo graph is used for
A)
taking X-ray photographs done
clear
B)
showing pictures done
clear
C)
demonstrating electrical pulses done
clear
D)
producing elementary particles done
clear
View Solution play_arrow
-
question_answer94)
Number of thermo electrons emitted per second from the cathode does not depend upon
A)
specific heat capacity of the cathode done
clear
B)
temperature of the cathode done
clear
C)
surface area of the cathode done
clear
D)
work function of the metal cathode done
clear
View Solution play_arrow
-
question_answer95)
Which of the following is formed under the earth by the decomposition of plant matter by anaerobic bacteria lying under water?
A)
Coal gas done
clear
B)
Petroleum gas done
clear
C)
Natural gas done
clear
D)
Producer gas done
clear
View Solution play_arrow
-
question_answer96)
Which of the following is not used as a rocket fuel?
A)
Synthetic rubber done
clear
B)
Liquid hydrogen done
clear
C)
Paraffin done
clear
D)
Liquid nitrogen done
clear
View Solution play_arrow
-
question_answer97)
Which of the following compound has a least heating value?
A)
Alcohol done
clear
B)
Biogas done
clear
C)
Wood done
clear
D)
Coal done
clear
View Solution play_arrow
-
question_answer98)
In the reaction, \[2C{{H}_{4}}+4{{O}_{2}}\to 2{{O}_{2}}+4{{H}_{2}}O+\] \[1780\,kJ\], the calorific value of methane is about
A)
55 kJ/g done
clear
B)
110 kJ/g done
clear
C)
110 J/g done
clear
D)
55 J/g done
clear
View Solution play_arrow
-
question_answer99)
When a cathode ray tube is operated at 2912 volt, then velocity of electrons is \[\text{3}.\text{2 }\times \text{ 1}{{0}^{7}}\] m/s. The velocity of cathode ray, if the tube is operated at 5824 volt, will be
A)
\[\text{4}.\text{48 }\times \text{ 1}{{0}^{\text{6}}}\text{ m}/\text{sec}\] done
clear
B)
\[\text{4}.\text{48 }\times \text{ 1}{{0}^{\text{7}}}\text{ m}/\text{sec}\] done
clear
C)
\[\text{8}.\text{44 }\times \text{ 1}{{0}^{\text{6}}}\text{ m}/\text{sec}\] done
clear
D)
\[\text{8}.\text{88 }\times \text{ 1}{{0}^{\text{7}}}\text{ m}/\text{sec}\] done
clear
View Solution play_arrow
-
question_answer100)
In a cathode ray oscillograph, the focusing of beam on the screen is achieved by
A)
convex lenses done
clear
B)
magnetic field done
clear
C)
electric potential done
clear
D)
All of these done
clear
View Solution play_arrow
-
question_answer101)
An electric field of intensity \[6\times 104volts/m\] is applied perpendicular to the direction of motion of the electron. A magnetic field of intensity \[\text{8 }\times \text{ 1}{{0}^{-\text{2}}}\text{ wb}/{{\text{m}}^{\text{2}}}\]is applied perpendicular to both the electric field and direction of motion of the electron. What is the velocity of the electron if it passes un deflected?
A)
\[\text{7}.\text{5 }\times \text{ 1}{{0}^{\text{5}}}\text{ m}/\text{s}\] done
clear
B)
\[\text{7}.\text{5 }\times \text{ 1}{{0}^{-\text{5}}}\text{ m}/\text{s}\] done
clear
C)
\[\text{6}\times \text{ 1}{{0}^{\text{4}}}\times \text{8 }\times \text{ l}{{\text{0}}^{-\text{2}}}\text{ m}/\text{s}\] done
clear
D)
It is never possible done
clear
View Solution play_arrow
-
question_answer102)
Kerosene burns more rapidly than coke because
A)
it has got more oxygen in it than coke done
clear
B)
it is a liquid hydrocarbon done
clear
C)
it has a low ignition temperature done
clear
D)
None of these done
clear
View Solution play_arrow
-
question_answer103)
Which of the following is not an example of spontaneous combustion?
A)
Burning of liquefied petroleum gas done
clear
B)
Fire caused in coal mines done
clear
C)
Dry white phosphorous liberates white fumes on exposure to air done
clear
D)
All of these done
clear
View Solution play_arrow
-
question_answer104)
Of the following, flames produced by a candle is
A)
Blue flame done
clear
B)
Non-luminous flame done
clear
C)
Light giving flame done
clear
D)
yellow luminous flame done
clear
View Solution play_arrow
-
question_answer105)
Unburnt carbon particles are present in the
A)
blue zone done
clear
B)
dark inner zone done
clear
C)
luminous zone done
clear
D)
non-luminous zone done
clear
View Solution play_arrow
-
question_answer106)
An electron is moving with velocity 107 m/s on a circular path of radius 0.57 cm in a magnetic field of\[\text{1}{{0}^{-\text{2}}}\text{ wb}/{{\text{m}}^{\text{2}}}\]. The value of elm for electron will be
A)
\[\text{1}\text{.76 }\times \text{ 1}{{0}^{\text{9}}}\text{ C}/\text{kg}\] done
clear
B)
\[\text{1}\text{.76 }\times \text{ 1}{{0}^{\text{1}0}}\text{ C}/\text{kg}\] done
clear
C)
\[\text{1}\text{.76 }\times \text{ 1}{{0}^{\text{11}}}\text{ C}/\text{kg}\] done
clear
D)
\[\text{1}\text{.76 }\times \text{ 1}{{0}^{\text{12}}}\text{ C}/\text{kg}\] done
clear
View Solution play_arrow
-
question_answer107)
Photoelectric effect can be explained only by assuming that
A)
light is a form of transverse waves done
clear
B)
light is a form of longitudinal waves done
clear
C)
light can be polarized done
clear
D)
light consists of quanta done
clear
View Solution play_arrow
-
question_answer108)
Light of a particular frequency o is incident on a metal surface. When the intensity of incident radiation is increased, then photoelectric current
A)
decreases done
clear
B)
increases done
clear
C)
remains unchanged done
clear
D)
sometimes increases and sometimes decreases done
clear
View Solution play_arrow
-
question_answer109)
Of the following a supporter of combustion is
A)
Cooking gas done
clear
B)
Nitrogen gas done
clear
C)
Oxygen gas done
clear
D)
Producer gas done
clear
View Solution play_arrow
-
question_answer110)
Biogas is a mixture of
A)
\[CO+{{H}_{2}}+C{{H}_{4}}\] done
clear
B)
\[C{{O}_{2}}+C{{H}_{4}}+{{H}_{2}}+{{H}_{2}}S\] done
clear
C)
\[CO+{{H}_{2}}\] done
clear
D)
\[C{{O}_{2}}+{{N}_{2}}\] done
clear
View Solution play_arrow
-
question_answer111)
Of the following, non-renewable source of energy is
A)
Coal done
clear
B)
Gobar gas done
clear
C)
Solar energy done
clear
D)
Tidal energy done
clear
View Solution play_arrow
-
question_answer112)
Of the following, renewable source of energy is
A)
Wood done
clear
B)
Petroleum done
clear
C)
Natural gas done
clear
D)
Uranium done
clear
View Solution play_arrow
-
question_answer113)
The photoelectric effect is based on the conservation of
A)
energy done
clear
B)
momentum done
clear
C)
mass done
clear
D)
angular momentum done
clear
View Solution play_arrow
-
question_answer114)
Photoelectric effect is described as the ejection of electrons from the surface of metal when
A)
it is heated to high temperature done
clear
B)
light of suitable wavelength falls on it done
clear
C)
electrons of a suitable velocity impinge or done
clear
D)
it is placed in a strong magnetic field done
clear
View Solution play_arrow
-
question_answer115)
The idea of quantum nature of light has emerged in an attempt to explain
A)
the thermal radiations of a black body done
clear
B)
the interference of light done
clear
C)
radioactivity done
clear
D)
thermionic emission done
clear
View Solution play_arrow
-
question_answer116)
The sources of energy which are being produced continuously in nature and are inexhaustible, are called
A)
conventional sources done
clear
B)
non-renewable sources done
clear
C)
non-conventional sources done
clear
D)
None of these done
clear
View Solution play_arrow
-
question_answer117)
The source of energy which is different from others is
A)
wood done
clear
B)
ailing water done
clear
C)
wind done
clear
D)
petroleum done
clear
View Solution play_arrow
-
question_answer118)
The source of energy, which is different from others is
A)
gobar gas done
clear
B)
vegetable refuse done
clear
C)
plants done
clear
D)
crude oil done
clear
View Solution play_arrow
-
question_answer119)
The source of energy which is different from others is
A)
natural gas done
clear
B)
petroleum done
clear
C)
uranium done
clear
D)
wood done
clear
View Solution play_arrow
-
question_answer120)
The source of energy which is different from others is
A)
lignite done
clear
B)
natural gas done
clear
C)
sun done
clear
D)
coal done
clear
View Solution play_arrow
-
question_answer121)
Mass of the photon at rest is
A)
\[\text{1}.\text{67 }\times \text{ 1}{{0}^{-\text{35}}}\text{ kg}\] done
clear
B)
one a. m. u. done
clear
C)
\[\text{9 }\times \text{ 1}{{0}^{-\text{31}}}\text{ kg}\] done
clear
D)
zero done
clear
View Solution play_arrow
-
question_answer122)
If the work function of the metal is \[\phi \] and the frequency of incident light is \[\upsilon \] there is no emission of photoelectrons when
A)
\[\upsilon =\frac{\phi }{h}\] done
clear
B)
\[\upsilon >\frac{\phi }{h}\] done
clear
C)
\[\upsilon <\frac{\phi }{h}\] done
clear
D)
\[\upsilon >=\frac{\phi }{h}\] done
clear
View Solution play_arrow
-
question_answer123)
Which one of the following statement about 'photon is correct?
A)
photon's rest mass is zero done
clear
B)
Momentum of photon is \[\frac{h\upsilon }{c}\] done
clear
C)
Photon's energy is \[h\upsilon \] done
clear
D)
All of these done
clear
View Solution play_arrow
-
question_answer124)
If work function of a photoelectric material is \[3.3\,eV\], then threshold frequency will be
A)
\[8\times {{10}^{14}}Hz\] done
clear
B)
\[8\times {{10}^{56}}Hz\] done
clear
C)
\[\text{8 }\times \text{ 1}{{0}^{\text{1}0}}\text{ Hz}\] done
clear
D)
\[\text{8 }\times \text{ 1}{{0}^{\text{11}}}\text{ Hz}\] done
clear
View Solution play_arrow
-
question_answer125)
Difference in the concentration of salts in water of two different seas is called
A)
ocean current done
clear
B)
nuclear fission done
clear
C)
oceanography done
clear
D)
salinity gradient done
clear
View Solution play_arrow
-
question_answer126)
Energy available due to the difference in the temperature of water at the surface of the ocean and at deeper levels is called
A)
tidal energy done
clear
B)
wind energy done
clear
C)
solar energy done
clear
D)
None of these done
clear
View Solution play_arrow
-
question_answer127)
The vast amount of sea weeds present in oceans may provide an endless source of
A)
nuclear energy done
clear
B)
methane done
clear
C)
thermal energy ocean done
clear
D)
None of these done
clear
View Solution play_arrow
-
question_answer128)
Energy of water is called
A)
mechanical energy done
clear
B)
hydroenergy done
clear
C)
solar energy done
clear
D)
None of these done
clear
View Solution play_arrow
-
question_answer129)
If energy of the photon is 10 eV, the momentum of the photon is
A)
\[\text{5}.\text{33 }\times \text{ 1}{{0}^{-\text{25}}}\text{ kg m}/\text{s}\] done
clear
B)
\[5.33\times {{10}^{-27}}m/s\] done
clear
C)
\[5.33\times {{10}^{-29}}Kg\,\,m/s\] done
clear
D)
\[5.33\times {{10}^{-23}}kg\,m/s\] done
clear
View Solution play_arrow
-
question_answer130)
The threshold wavelength for lithium is 5250\[\overset{\text{o}}{\mathop{\text{A}}}\,\]. For photo emission to take place, the wavelength of the incident light must be
A)
more than \[\text{525}0\overset{\text{o}}{\mathop{\text{A}}}\,\] done
clear
B)
exactly equal to \[\text{525}0\text{ }\overset{\text{o}}{\mathop{\text{A}}}\,\] done
clear
C)
equal to or more than \[\text{525}0\text{ }\overset{\text{o}}{\mathop{\text{A}}}\,\] done
clear
D)
equal to or less than \[\text{525}0\text{ }\overset{\text{o}}{\mathop{\text{A}}}\,\] done
clear
View Solution play_arrow
-
question_answer131)
Relation between energy, E and momentum, p of the photon is given by\[E=hv\,and\,p=\frac{h}{\lambda }\] The velocity of the photon will be
A)
\[\frac{E}{p}\] done
clear
B)
\[Ep\] done
clear
C)
\[{{\left( \frac{E}{p} \right)}^{2}}\] done
clear
D)
\[{{\left( \frac{E}{p} \right)}^{\frac{1}{2}}}\] done
clear
View Solution play_arrow
-
question_answer132)
The generation of electricity from water energy
A)
will never get exhausted done
clear
B)
will not produce any environmental pollution done
clear
C)
is renewable source of energy done
clear
D)
All the above are correct done
clear
View Solution play_arrow
-
question_answer133)
Energy available from the oceans is
A)
OTE done
clear
B)
tidal energy done
clear
C)
sea-waves energy done
clear
D)
all of these done
clear
View Solution play_arrow
-
question_answer134)
Which of the following is not a form of oceanic energy?
A)
Energy from biomass done
clear
B)
Tidal energy done
clear
C)
Ocean thermal energy done
clear
D)
Solar energy done
clear
View Solution play_arrow
-
question_answer135)
At many places in the ocean, the difference in temperatures between the water 'at the surface of ocean' and 'at deeper levels' is up to
A)
\[120{}^\circ C\] done
clear
B)
\[80{}^\circ C\] done
clear
C)
\[50{}^\circ C\] done
clear
D)
\[20{}^\circ C\] done
clear
View Solution play_arrow
-
question_answer136)
The oceans cover almost _______ percent of the surface of earth with water and act as a vast collector of________ energy.
A)
71, chemical done
clear
B)
97, solar done
clear
C)
71, solar done
clear
D)
17, hydroenergy done
clear
View Solution play_arrow
-
question_answer137)
Photoelectric work function of a metal is 1 eV and light of wavelength \[\lambda \] = \[\text{3000 }\overset{\text{o}}{\mathop{\text{A}}}\,\] falls on it. The photoelectrons come out with velocity
A)
\[\text{1}{{0}^{\text{2}}}\text{ m}/\text{s}\] done
clear
B)
\[\text{1}{{0}^{\text{4}}}\text{ m}/\text{s}\] done
clear
C)
\[\text{1}{{0}^{\text{6}}}\text{ Ws}\] done
clear
D)
\[\text{1}{{0}^{\text{8}}}\text{ m}/\text{s}\] done
clear
View Solution play_arrow
-
question_answer138)
Number of photons emitted in 10 hours by 60 W sodium lamp is \[(\lambda =5893\overset{\circ }{\mathop{A}}\,)\]
A)
\[\text{6}.\text{4}0\text{ }\times \text{ 1}{{0}^{\text{22}}}\] done
clear
B)
\[\text{6}.\text{4}0\text{ }\times \text{ 1}{{0}^{\text{24}}}\] done
clear
C)
\[\text{4}.\text{6}0\text{ }\times \text{ 1}{{0}^{\text{22}}}\] done
clear
D)
\[\text{4}.\text{6}0\text{ }\times \text{ 1}{{0}^{\text{24}}}\] done
clear
View Solution play_arrow
-
question_answer139)
If work function of a metal surface is 4.2 eV, then maximum wavelength which can eject electrons from this metal surface is
A)
\[\text{3}0\text{79}\overset{\circ }{\mathop{A}}\,\] done
clear
B)
\[~\text{4116}\overset{\circ }{\mathop{A}}\,\] done
clear
C)
\[\text{2956}\overset{\circ }{\mathop{A}}\,\] done
clear
D)
\[\text{5}0\text{88}\overset{\circ }{\mathop{A}}\,\] done
clear
View Solution play_arrow
-
question_answer140)
The surface of some material is radiated in turn, by waves of \[\lambda =3.5\times {{10}^{-7}}m\]and \[\lambda =5.4\times {{10}^{-7}}m\]respectively. The ratio of the stopping potential in the two cases is 2 : 1. The work function of the metal is
A)
\[1.05\,eV\] done
clear
B)
\[1.5\,eV\] done
clear
C)
\[2.05\,eV\] done
clear
D)
\[2.5\,eV\] done
clear
View Solution play_arrow
-
question_answer141)
At present, the contribution of hydroelectricity to the total power generation in India is
A)
a little more than 23% done
clear
B)
a little more than 35% done
clear
C)
a little more than 47% done
clear
D)
none of these done
clear
View Solution play_arrow
-
question_answer142)
Which of the following is not a high wind-energy region of India?
A)
Bay of Bengal done
clear
B)
Gujarat done
clear
C)
The Arabian sea Islands done
clear
D)
Punjab done
clear
View Solution play_arrow
-
question_answer143)
Wind-energy map gives information about the
A)
causes of wind done
clear
B)
amount of rainfall done
clear
C)
intensity of earthquake done
clear
D)
none of these done
clear
View Solution play_arrow
-
question_answer144)
If ultra-violet radiation of 6.2 eV falls on an aluminium surface (work function 4.2 eV ), then K.E. in joules of the fastest electron emitted is approximately
A)
\[\text{3 }\times \text{ 1}{{0}^{-\text{23}}}\] done
clear
B)
\[\text{3 }\times \text{ 1}{{0}^{-\text{21}}}\] done
clear
C)
\[\text{3 }\times \text{ 1}{{0}^{-\text{19}}}\] done
clear
D)
\[\text{3 }\times \text{ 1}{{0}^{-\text{17}}}\] done
clear
View Solution play_arrow
-
question_answer145)
The work function of a metal is 2.5 eV. If tin radiation of wavelength 4000A falls on it, then energy of emitted photoelectrons will be
A)
0.402 eV done
clear
B)
0.204 eV done
clear
C)
0.306 eV done
clear
D)
\[0.\text{6}0\text{3 eV}\] done
clear
View Solution play_arrow
-
question_answer146)
If work function of cesium is 1.8 eV, and light of \[\text{5}000\overset{\circ }{\mathop{A}}\,\] is incident on it, then maximum velocity of emitted electrons is
A)
\[\text{5 }\times \text{ 1}{{0}^{\text{3}}}\text{ m}/\text{s}\] done
clear
B)
\[\text{5 }\times \text{ 1}{{0}^{\text{4}}}\text{ m}/\text{s}\] done
clear
C)
\[\text{5}.0\text{ }\times \text{ 1}{{0}^{\text{5}}}\text{ m}/\text{s}\] done
clear
D)
\[\text{5 }\times \text{ 1}{{0}^{\text{6}}}\text{ m}/\text{s}\] done
clear
View Solution play_arrow
-
question_answer147)
Of the following, the fuel having greatest calorific value is
A)
Petrol done
clear
B)
Kerosene done
clear
C)
Biogas done
clear
D)
Coke done
clear
View Solution play_arrow