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

Question # 1

The length contraction happens only

Opposite to the direction of motion A
along the direction of motion B
perpendicular to the direction of motion C
In any direction D

Question # 2

The inside cavity of the black body is

painted white A
painted silver B
blackened with soot C
painted red D

Question # 3

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 # 4

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 # 5

The concept of direction and position are purely

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

Question # 6

A non-inertial frame of reference is one, in which

law of inertial is valid A
all laws of physics are the same in all frames B
a>0 or a<0 C
a=0 D

Question # 7

The idea of quantization of energy was proposed by:

Einstein A
Max.Planck B
Maxwell C
Bohr D
Rutherford E

Question # 8

When a platinum wire is heated, it appears dull red at about

500°C A
900°C B
1100°C C
1300°C D

Question # 9

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 # 10

The unit of work function is:

Joule A
Electron volt B
That of threshold frequency C
Both (A) and (B) D
None of these E

Question # 11

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 # 12

The nature of radiations emitted by a hot body depends upon its:

Metarial A
Temperature B
colour C
Volume D
Length E

Question # 13

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 # 14

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

Remains constant A
Decreases B
Increases to infinity C
Reduced to zero D

Question # 15

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 # 16

When a platinum wire is heated, it appears white at

1600°C A
900°C B
1100°C C
1300°C D

Question # 17

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 # 18

If the radius of first orbit of hydrogen atom is 0.53° A the radius of second orbit will be

2.120°A A
0.212°A B
21.2°A C
0.14°
a
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

Converse of pair production is known as

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

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 # 23

An inertial frame is that frame in which

a>0 A
a=0 B
a<0 C
none of these D

Question # 24

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 # 25

According to the special theory of relativity, time is

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

Question # 26

An electron is accelerated through a potential difference of 50v. its de-Brogile wavelength is

1.66 x 10^-29m A
1.74 x 10^-10cm B
17.4 x 10^-6m C
1.74 x 10^-10m D

Question # 27

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 # 28

Max plank founded a mathematical model resulting in an equation that describes the shape of observed black body radiation curves exactly, in

1890 A
1895 B
1900 C
1905 D

Question # 29

When platinum wire is heated, then at the temperature of 500 ^oC, it becomes:

Yellow A
Orange red B
Dull red C
White D
Cherry red E

Question # 30

Which of the following phenomenon proves the particle nature of light

interference A
diffraction B
photoelectric effect C
none of these D

Sr.#	Question	Answer
1	As the light shines on the metal surface, the electrons are ejected	A. slowly B. instantaneously C. either of these D. none of these
2	Compton studied the scattering of x-rays by loosely bound electrons from:	A. NaCl crystal B. Graphite crystal C. Zirconia D. Copper crystal
3	The threshold frequency of sodium is 6 x 10⁶MHz. The cut-off wavelength for this metal will be	A. 500 m B. 500 nm C. 500 km D. 500 cm
4	If the radius of first orbit of hydrogen atom is 0.53° A the radius of second orbit will be	A. 2.120°A B. 0.212°A C. 21.2°A D. 0.14° a
5	When platinum wire is heated, then at the temperature of 500 ^oC, it becomes:	A. Yellow B. Orange red C. Dull red D. White
6	Absolute motion cannot be detected	A. in its own frame of references B. in a different frame of references C. both in its frame and different frame of references D. none of these
7	The Nobel Prize on the explanation of photoelectric effect was awarded to:	A. Max. Planck B. Maxwell C. Bohr D. Rutherford
8	If A represents linear momentum and c, the velocity of light, then unit of pc in international system of units is:	A. Newton B. Joule C. Joule-Sec D. Joule-s^-1
9	Electromagnetic -radiation means:	A. Photons B. protons C. Electrons D. Mesons
10	The way through which electromagnetic radiations or photons interact with matter depends upon their:	A. Wavelength B. Frequency C. Energy D. Temperature

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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

The length contraction happens only

The inside cavity of the black body is

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

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

The concept of direction and position are purely

A non-inertial frame of reference is one, in which

The idea of quantization of energy was proposed by:

When a platinum wire is heated, it appears dull red at about

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

The unit of work function is:

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

The nature of radiations emitted by a hot body depends upon its:

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

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

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

When a platinum wire is heated, it appears white at

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

If the radius of first orbit of hydrogen atom is 0.53° A the radius of second orbit will be

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

Converse of pair production is known as

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

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

An inertial frame is that frame in which

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

According to the special theory of relativity, time is

An electron is accelerated through a potential difference of 50v. its de-Brogile wavelength is

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

Max plank founded a mathematical model resulting in an equation that describes the shape of observed black body radiation curves exactly, in

When platinum wire is heated, then at the temperature of 500 oC, it becomes:

Which of the following phenomenon proves the particle nature of light

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

When platinum wire is heated, then at the temperature of 500 ^oC, it becomes: