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

Question # 1

A photon is considered to have

Momentum A
Energy B
Wavelength C
All of the above D

Question # 2

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 # 3

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

1916 A
1919 B
1921 C
1923 D

Question # 4

In photoelectric effect the energy of ejected electrons depend on

The frequency A
The intensity B
Both frequency and intensity C
None of these D

Question # 5

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 # 6

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 # 7

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 # 8

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 # 9

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 # 10

The idea of quantization of energy was proposed by:

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

Question # 11

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 # 12

The positron was discovered by:

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

Question # 13

de-Broglies hypthesis was experimentally verified by

Maxwell A
Compton B
Einstein C
Davison and Germer D

Question # 14

A bar 1.0 m in length and located along x-axix moves with a speed of 0.75 c with respect to a stationary observer. The length of the bar as measured by the stationary observer is

1.66 m A
1.0 m B
0.66 m C
2.66 m D

Question # 15

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 # 16

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 # 17

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 # 18

The stopping voltage for a certain metal is 100 volts, then the work function for the cathode plate is

100 J A
1.6 x 10^-17J B
100 eV C
1.6 x 10^-17eV D

Question # 19

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 # 20

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 # 21

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 # 22

If a body reaches a speed equal to the speed of light, then its mass will became

zero A
very small B
infinity C
none of these D

Question # 23

The existence of position was predicted by Dirace in

1920 A
1925 B
1930 C
1928 D

Question # 24

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 # 25

Position was discovered by Carl Anderson in

1920 A
1925 B
1928 C
1932 D

Question # 26

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

Question # 27

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 # 28

When a platinum wire is heated, it appears orange red at

500°C A
900°C B
1100°C C
1300°C D

Question # 29

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 # 30

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

Sr.#	Question	Answer
1	de-Broglies hypthesis was experimentally verified by	A. Maxwell B. Compton C. Einstein D. Davison and Germer
2	An inertial frame is that frame in which	A. a>0 B. a=0 C. a<0 D. none of these
3	Max plank founded a mathematical model resulting in an equation that describes the shape of observed black body radiation curves exactly, in	A. 1890 B. 1895 C. 1900 D. 1905
4	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
5	Strictly speaking, the earth is:	A. An accelerated frame of reference B. A non-inertial frame of reference C. An inertial frame of reference D. ^{A non-accelerated frame of reference}
6	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
7	The photon of radio-waves has energy of about	A. 1 Me V B. 1 Ke v C. 10^-10e v D. 10¹⁰e v
8	Albert Einstein got the Nobel prize in physics for his explanation of photoelectric effect in	A. 1916 B. 1919 C. 1921 D. 1923
9	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
10	The Nobel Prize on the explanation of photoelectric effect was awarded to:	A. Max. Planck B. Maxwell C. Bohr D. Rutherford

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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