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

Question # 1

When a position comes close to an electron they annihilate into

one photon A
two photons which travel in the same direction B
two photons which travels in the opposite direction C
two photons which travel in any direction D

Question # 2

A black body is

an ideal absorber A
an ideal radiator B
both of them C
none of them D

Question # 3

As compared to the distance measured by an observer on Earth, the distance from Earth to a star measured by an observer in a moving spaceship would seem:

Smaller A
Lerger B
Same C
Much larger D
None of these E

Question # 4

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 # 5

Wave nature of particle was proposed by

Einstein A
Plank B
De-Brogile C
Max well D

Question # 6

When monochromatic light is allowed to fall on cathode, it begins to emit electrons, these electrons are called

thermoionic electrons A
free electrons B
photoelectrons C
slow electrons D

Question # 7

The Einstein's changes in length, mass and time are not observed in common life because

We dont observer then seriously A
The masses are too large B
Their speed is too small than the speed of right C
All of the above D

Question # 8

Compton was awarded Nobel prize in physics in

1921 A
1923 B
1925 C
1927 D

Question # 9

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 # 10

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 # 11

The mass of an object will be doubled at speed

1.6 x 10⁸ms^-1 A
2.6 X 10⁸ms^-1 B
2.6 x 10⁷ms^-1 C
2.6 x 10⁹ms^-1 D

Question # 12

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 # 13

Position was discovered by Carl Anderson in

1920 A
1925 B
1928 C
1932 D

Question # 14

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 # 15

Momentum is a parameter associated with

wave motion A
particle motion B
neither wave nor particle motion C
none of these D

Question # 16

The existence of position was predicted by Dirace in

1920 A
1925 B
1930 C
1928 D

Question # 17

The location and speed anywhere on earth can now be determined using relativistic effects by NAVISTAR to an accuracy of

2 cm/s A
20 cm/s B
200 cm/s C
2000 cm/s D

Question # 18

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 # 19

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 # 20

The concept of direction is purely:

Absolute A
Relative B
Relative to stars always C
Relative to the sun always D
None of these E

Question # 21

The whole shape of the black body spectrum for all wavelengths was explained by the formula proposed by

Max plank A
Newton B
Einstein C
J.J. Thomson D

Question # 22

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 # 23

Electromagnetic -radiation means:

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

Question # 24

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 # 25

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 # 26

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 # 27

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 # 28

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 # 29

The intensity of emitted energy (with wavelength) radiated from a black body at different temperatures was initially measured by:

Lummer A
Planck B
Pringsheim C
Both (A ) and (B) D
Both (A) and (C) E

Question # 30

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

Sr.#	Question	Answer
1	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
2	The whole shape of the black body spectrum for all wavelengths was explained by the formula proposed by	A. Max plank B. Newton C. Einstein D. J.J. Thomson
3	When a platinum wire is heated, it appears yellow at	A. 1600°C B. 900°C C. 1100°C D. 1300°C
4	Photoelectrons are emitted when ultraviolet light falls on:	A. Casium B. Silver C. Potassium D. Any of these
5	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
6	Victor de-Brogile received the Nobel prize in physics in	A. 1925 B. 1929 C. 1932 D. 1935
7	The idea of quantization of energy was proposed by:	A. Einstein B. Max.Planck C. Maxwell D. Bohr
8	Compton was awarded Nobel prize in physics in	A. 1921 B. 1923 C. 1925 D. 1927
9	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
10	The value of threshold frequency for different metals is	A. different B. same C. may be different or may be same 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

When a position comes close to an electron they annihilate into

A black body is

As compared to the distance measured by an observer on Earth, the distance from Earth to a star measured by an observer in a moving spaceship would seem:

The photon of radio-waves has energy of about

Wave nature of particle was proposed by

When monochromatic light is allowed to fall on cathode, it begins to emit electrons, these electrons are called

The Einstein's changes in length, mass and time are not observed in common life because

Compton was awarded Nobel prize in physics in

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

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

The mass of an object will be doubled at speed

Pair production is the phenomenon in which

Position was discovered by Carl Anderson in

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

Momentum is a parameter associated with

The existence of position was predicted by Dirace in

The location and speed anywhere on earth can now be determined using relativistic effects by NAVISTAR to an accuracy of

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

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

The concept of direction is purely:

The whole shape of the black body spectrum for all wavelengths was explained by the formula proposed by

The value of threshold frequency for different metals is

Electromagnetic -radiation means:

The general theory of relativity treats problems involving

The length contraction happens only

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

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

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

The intensity of emitted energy (with wavelength) radiated from a black body at different temperatures was initially measured by:

The unit of work function is:

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