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

Question # 1

An intertial frame of reference is a frame of reference which is

at rest A
moving with uniform velocity B
either at rest or moving with uniform velocity C
none of these D

Question # 2

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 # 3

The value of the Stephen's constant for black body radiations is given by

5.6 x 10⁸Wm^-2K^-4 A
5.67 x 10^-8Wm^-2K^-4 B
2.9 x 10^-3mK C
2.9 x 10³mK D

Question # 4

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 # 5

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 # 6

Compton derived an expression to find compton shift by applying to the process, the law of conservation of:

Energy only A
Momentum only B
Mass only C
Charge only D
Both (A) and (B) E

Question # 7

Due to relative motion of observer and the frame of reference of events, time always:

Dilates itself A
Contracts itself B
Stretches itself C
Both (A) and (C) D
None of these E

Question # 8

The threshold frequency of sodium is 6 x 10⁶MHz. The cut-off wavelength for this metal will be

500 m A
500 nm B
500 km C
500 cm D
None of these E

Question # 9

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 # 10

The photon of radio-waves has energy of about

1 Me V A
1 Ke v B
10^-10e v C
10¹⁰e v D

Question # 11

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 # 12

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

Question # 13

The concept of direction and position are purely

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

Question # 14

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 # 15

In order to produce pair production, a photon must have a energy

0.511 Me v A
0.256 Me v B
1.02 Me v C
0.956 Me v D

Question # 16

Absolute motion cannot be detected

in its own frame of references A
in a different frame of references B
both in its frame and different frame of references C
none of these D

Question # 17

The analysis of the distribution of wavelengths of the radiation emitted from a hot body set the foundation of new mechanics, known as

classical mechanics A
Newtonian mechanics B
quantum mechanics C
statistical mechanics D

Question # 18

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 # 19

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 # 20

According to the special theory of relativity, time is

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

Question # 21

Photoelectric effect takes place with a photon of:

Very high energy A
Very low energy B
Low energy C
High energy D
None of these E

Question # 22

The mass 'm' of a body moving at 0.8 c (whose rest mass is mo) becomes

2 mo A
1.67 mo B
0.67 mo C
2.67 mo D

Question # 23

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 # 24

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 # 25

Max Planck received the Nobel Prize for his discovery of energy quants in:

1718 AD A
1918 AH B
1818 AD C
1918 AD D
None of these E

Question # 26

The existence of position was predicted by Dirace in

1920 A
1925 B
1930 C
1928 D

Question # 27

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 # 28

Photoelectrons are emitted when ultraviolet light falls on:

Casium A
Silver B
Potassium C
Any of these D
None of these E

Question # 29

Practically the quantity v/c is always:

less than one A
Equal to one B
Greater then one C
all of these D
None of these E

Question # 30

Which of the following is not an example of intertial frame

a body placed on the surface of earth A
a body placed in a car moving with uniform velocity B
a body placed in a car moving with same acceleration C
none of these D

Sr.#	Question	Answer
1	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
2	The special theory of relativity is based on:	A. Four postulates B. Three postulates C. Two postulates D. One postulate
3	Max Planck received the Nobel Prize for his discovery of energy quants in:	A. 1718 AD B. 1918 AH C. 1818 AD D. 1918 AD
4	Newton's law of motion do not hold in	A. an accelerated frame of reference B. an unaccelerated frame of reference C. both of these D. none of these
5	In photoelectric effect the energy of ejected electrons depend on	A. The frequency B. The intensity C. Both frequency and intensity D. None of these
6	According to the special theory of relativity	A. mass and energy are same entities B. mass and energy are same entities but interconverible C. mass and energy are different entities but interconverible D. mass and energy are different entities but non-interconveritble
7	There is certain frequency below which no electrons are emitted from the metal surface, this frequency is known as	A. maximum frequency B. minimum frequency C. threshold frequency 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	A particle having mass and charge equal to that of an electron is called:	A. Proton B. Positron C. Pion D. Pi-meson
10	According to the special theory of relativity, time is	A. absolute quantity B. not absolute quantity C. constant quantity D. none of these

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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