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

In the compton's effect, it is found that the wavelength of incident x-rays is

greater than the wavelength of scattered x-rays A
equal to the wavelength of scattered x-rays B
less than the wavelength of scattered x-rays C
any one of these D

Question # 3

The Stephen-Boltzmann law for the black body radiation is given by

E = T² A
E = -T² B
E = T⁴ C
E = -T⁴ D

Question # 4

Intensity of light determines the:

Energy of each photon A
Number of photons B
Speed of photons C
Size of photons D
None of these E

Question # 5

Position was discovered by Carl Anderson in

1920 A
1925 B
1928 C
1932 D

Question # 6

According to the de-Brogile relation, an object of large mass and ordinary speed has

very small wavelength A
very large wavelength B
very small frequency C
all of these D

Question # 7

Compton was awarded Nobel prize in physics in

1921 A
1923 B
1925 C
1927 D

Question # 8

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 # 9

The concept of direction and position are purely

absolute A
relative B
absolute or relative C
none of these D

Question # 10

the dilation of time applies to the timing processes which are:

Physical A
Chemical B
Biological C
All of these D
None of these E

Question # 11

Victor de-Brogile received the Nobel prize in physics in

1925 A
1929 B
1932 C
1935 D

Question # 12

From the theory of relativity, momentum p of the photon is related to energy as

p = hfc A
p = hf/c B
p = f(hc,f) C
p = cf/h D

Question # 13

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 # 14

The Nobel Prize on the explanation of photoelectric effect was awarded to:

Max. Planck A
Maxwell B
Bohr C
Rutherford D
None of these E

Question # 15

If you are moving at relativistic speed between two points that are a fixed distance apart, then the distance between the two points appers

larger A
shorter B
equal C
none of these D

Question # 16

Strictly speaking, the earth is:

An accelerated frame of reference A
A non-inertial frame of reference B
An inertial frame of reference C
^{A non-accelerated frame of reference} D
Both (A) and (B) E

Question # 17

Newton's law of motion do not hold in

an accelerated frame of reference A
an unaccelerated frame of reference B
both of these C
none of these D

Question # 18

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 # 19

The positron was discovered by:

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

Question # 20

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

1916 A
1919 B
1921 C
1923 D

Question # 21

When the atomic particle are moving with velocities approaching that of light:

Newton's laws become valid A
Relativistic effects become prominent B
Botha(A) and (B) are valid C
Neither (A)nor (B) D
There mass becomes zero. E

Question # 22

When a platinum wire is heated, it appears yellow at

1600°C A
900°C B
1100°C C
1300°C D

Question # 23

The emission of electrons from a metal surface when exposed to light of suitable frequency is called the

pair production A
Compton effect B
photoelectric effect C
relativity D

Question # 24

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 # 25

Compton shift refers to:

Photon A
Meson B
Proton C
Positron D
Both (B) and (D) E

Question # 26

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 # 27

According to the special theory of relativity, a moving clock

runs faster A
runs slower B
neither runs faster nor slower C
all of these D

Question # 28

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 # 29

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 # 30

A particle of mass 5.0 mg moves with a speed of 8.0 m/s. Its de-Brogile wavelength is

1.66 m A
1.66 x 10^-10m B
1.66 x 10^-29cm C
1.66 x 10^-29m D

Sr.#	Question	Answer
1	When a position comes close to an electron they annihilate into	A. one photon B. two photons which travel in the same direction C. two photons which travels in the opposite direction D. two photons which travel in any direction
2	According to the special theory of relativity, time is	A. absolute quantity B. not absolute quantity C. constant quantity D. none of these
3	If you are moving at relativistic speed between two points that are a fixed distance apart, then the distance between the two points appers	A. larger B. shorter C. equal D. none of these
4	A high temperature, the proportion of shorter wavelengths radiation, emitted by the body	A. decreases B. first increases then decreases C. increases D. any one of them
5	From the theory of relativity, momentum p of the photon is related to energy as	A. p = hfc B. p = hf/c C. p = f(hc,f) D. p = cf/h
6	Position was discovered by Carl Anderson in	A. 1920 B. 1925 C. 1928 D. 1932
7	the dilation of time applies to the timing processes which are:	A. Physical B. Chemical C. Biological D. All of these
8	The intensity of emitted energy (with wavelength) radiated from a black body at different temperatures was initially measured by:	A. Lummer B. Planck C. Pringsheim D. Both (A ) and (B)
9	The concept of direction is purely:	A. Absolute B. Relative C. Relative to stars always D. Relative to the sun always
10	When a platinum wire is heated, it appears orange red at	A. 500°C B. 900°C C. 1100°C D. 1300°C

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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