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

Question # 1

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 # 2

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 # 3

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 # 4

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 # 5

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 # 6

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

500°C A
900°C B
1100°C C
1300°C D

Question # 7

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 # 8

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 # 9

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 # 10

Compton was awarded Nobel prize in physics in

1921 A
1923 B
1925 C
1927 D

Question # 11

When a position comes close to an electron they annihilate into photons such that

each photon has energy 0.51 Me v A
each photon has energy 1.02 Me v B
each photon has energy 0.25 Me v C
none of these D

Question # 12

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 # 13

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 # 14

The energy of photon 'E' is proported to

The magnetic field H A
The electric field E B
Both the electric and magnetic field H and E C
Frequency D

Question # 15

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 # 16

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 # 17

When a platinum wire is heated, it appears yellow at

1600°C A
900°C B
1100°C C
1300°C D

Question # 18

According to the electromagnetic wave theory of light, increasing the intensity of incident light should increase the

number of photoelectrons A
size of the photoelectrons B
charge on photoelectrons C
K.E of photoelectrons D

Question # 19

When a high energy photon interact with a metal, which of the following effect is most likely to be taken place

pair production A
photoelectric effect B
Compton effect C
None of these D

Question # 20

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 # 21

The year when A.H. compton was awarded Nobel Prize is:

1923 A
1927 B
1931 C
1935 D
None of these E

Question # 22

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 # 23

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 # 24

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 # 25

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 # 26

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 # 27

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 # 28

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 # 29

Position and momentum of a particle cannot both be measured simultaneously with perfect accuracy. This is the statement of

photoelectric effect A
pair production B
Compton effect C
uncertainty principle D

Question # 30

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

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	A particle having mass and charge equal to that of an electron is called:	A. Proton B. Positron C. Pion D. Pi-meson
3	The value of the plank's constant 'h' is given by	A. 1.6 x 10^-19J B. 1.67 x 10^-27Kg C. 6.63 x 10³⁴Js D. 6.63 x 10^-34Js
4	Momentum is a parameter associated with	A. wave motion B. particle motion C. neither wave nor particle motion D. none of these
5	Davision and Germer performed experiment to verify	A. de-Brogile hypothesis B. theory of relativity C. Newton's law of gravitation D. Mass-energy relation
6	Compton derived an expression to find compton shift by applying to the process, the law of conservation of:	A. Energy only B. Momentum only C. Mass only D. Charge only
7	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
8	When low energy photon interact with a metal,which of the following effect is likely to be taken place	A. pair production B. photoelectric C. Compton effect D. None of these
9	Converse of pair production is known as	A. Compton effect B. annihilation of matter C. photoelectric effect D. none of these
10	According to Einstein, with the great increase in the speed of the body, the relativistic mass of the body	A. Remains constant B. Decreases C. Increases to infinity D. Reduced to zero

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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