ECAT Pre General Science Chapter 19 online mcq test with answers for Physics chapter 19 (Dawn of Modern Physics)

Question # 1

If a material object moves with the speed of light 'C' its mass becomes

Equal to its rest mass A
Four times of its rest mass B
Double of its rest mass C
Infinite D

Question # 2

Electromagnetic -radiation means:

Photons A
protons B
Electrons C
Mesons D
None of these E

Question # 3

According to Einstein, with the great increase in the speed of the body the relativistic length of the body

Remains constant A
Decreases B
Increases C
Reduces to zero D

Question # 4

The special theory of relativity treats problems invoving

inertial frame of references A
accelerating frame of references B
both of these C
none of these D

Question # 5

Converse of pair production is known as

Compton effect A
annihilation of matter B
photoelectric effect C
none of these D

Question # 6

According to the special theory of relativity, time is

absolute quantity A
not absolute quantity B
constant quantity C
none of these D

Question # 7

Albert Einstein got the Nobel prize in physics for his explanation of photoelectric effect in

1916 A
1919 B
1921 C
1923 D

Question # 8

The energy of a photon is represented by

h/c² A
h/T B
hc² C
hf/c² D

Question # 9

As the light shines on the metal surface, the electrons are ejected

slowly A
instantaneously B
either of these C
none of these D

Question # 10

When platinum wire is heated, it appears cherry red at

1600°C A
900°C B
1100°C C
1300°C D

Question # 11

The positron was discovered by:

In cosmic radiation A
In 1932 B
By Carl Anderson C
All above D
By direc E

Question # 12

Compton studied the scattering of x-rays by loosely bound electrons from:

NaCl crystal A
Graphite crystal B
Zirconia C
Copper crystal D
None of these E

Question # 13

The value of threshold frequency for different metals is

different A
same B
may be different or may be same C
none of these D

Question # 14

The general theory of relativity treats problems involving

inertial frame of references A
accelerating frame of references B
both of these C
none of these D

Question # 15

The existence of position was predicted by Dirace in

1920 A
1925 B
1930 C
1928 D

Question # 16

The special theory of relativity is based on:

Four postulates A
Three postulates B
Two postulates C
One postulate D
None of these E

Question # 17

There is no way to detect:

Absolute uniform motion A
Accelerated motion B
State rest C
State of motion D
None of these E

Question # 18

The photoelectric effect, the maximum energy of photoelectrons depends on the

particular metal surface A
frequency of incident light B
both of them C
none of them D

Question # 19

The energy of a photon in a beam of infrared radiation of wavelength 1240 nm is

100 ev A
10⁶e v B
10³e v C
1.0 e v D

Question # 20

Which of the following phenomenon proves the particle nature of light

interference A
diffraction B
photoelectric effect C
none of these D

Question # 21

There is certain frequency below which no electrons are emitted from the metal surface, this frequency is known as

maximum frequency A
minimum frequency B
threshold frequency C
all of these D

Question # 22

According to the Max plank, energy is redialed or absorbed in

discrete packets A
continuous waves B
either of them C
none of these D

Question # 23

At the temperature, a body emits radiation which is principally

of long wavelengths in the visible region A
of long wavelengths in the invisible infrared region B
of short wavelength in invisible ultraviolet region C
none of these D

Question # 24

According to the electromagnetic wave theory of light, increasing the intensity of incident light should increase the

number of photoelectrons A
size of the photoelectrons B
charge on photoelectrons C
K.E of photoelectrons D

Question # 25

When low energy photon interact with a metal,which of the following effect is likely to be taken place

pair production A
photoelectric B
Compton effect C
None of these D

Question # 26

The way through which electromagnetic radiations or photons interact with matter depends upon their:

Wavelength A
Frequency B
Energy C
Temperature D
All of these E

Question # 27

0.1 kg mass will be equivalent to the energy

9 x 10¹⁵J A
5 x 10⁸J B
6 x 10¹⁶J C
9 x 10^-16J D

Question # 28

Pair production is the phenomenon in which

matter is converted into energy A
energy is converted into matter B
light is converted into electrical energy C
electrical energy is converted into light D

Question # 29

Position was discovered by Carl Anderson in

1920 A
1925 B
1928 C
1932 D

Question # 30

the symbol to be used in relativity problems denotes:

Dilated time A
Proper time B
Life time C
Half time D
None of these E

Sr.#	Question	Answer
1	When platinum wire is heated, it appears cherry red at	A. 1600°C B. 900°C C. 1100°C D. 1300°C
2	The nature of radiations emitted by a hot body depends upon its:	A. Metarial B. Temperature C. colour D. Volume
3	If a body reaches a speed equal to the speed of light, then its mass will became	A. zero B. very small C. infinity D. none of these
4	When a high energy photon interact with a metal, which of the following effect is most likely to be taken place	A. pair production B. photoelectric effect C. Compton effect D. None of these
5	The special theory of relativity treats problems invoving	A. inertial frame of references B. accelerating frame of references C. both of these D. none of these
6	the symbol to be used in relativity problems denotes:	A. Dilated time B. Proper time C. Life time D. Half time
7	A particle of mass 5.0 mg moves with a speed of 8.0 m/s. Its de-Brogile wavelength is	A. 1.66 m B. 1.66 x 10^-10m C. 1.66 x 10^-29cm D. 1.66 x 10^-29m
8	According to Einstein, with the great increase in the speed of the body the relativistic length of the body	A. Remains constant B. Decreases C. Increases D. Reduces to zero
9	The unit of work function is:	A. Joule B. Electron volt C. That of threshold frequency D. Both (A) and (B)
10	The energy of a photon in a beam of infrared radiation of wavelength 1240 nm is	A. 100 ev B. 10⁶e v C. 10³e v D. 1.0 e v

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ECAT Pre General Science Physics Chapter 19 MCQ Test With Answer

MCQ's Test For ECAT Pre General Science Physics Chapter 19 Dawn of Modern Physics

ECAT Pre General Science Physics Chapter 19 Dawn of Modern Physics