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

Question # 1

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 # 2

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 # 3

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 # 4

An inertial frame is that frame in which

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

Question # 5

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 # 6

Electromagnetic radiation or photons interact with matter in

two distinct ways A
three distinct ways B
four distinct ways C
five distinct ways 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

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 # 9

Davision and Germer performed experiment to verify

de-Brogile hypothesis A
theory of relativity B
Newton's law of gravitation C
Mass-energy relation D

Question # 10

Current, voltage, resistance measuring circuit is connected with the galvanometer with the help of switch, known as

ON switch A
off switch B
function switch C
none of these D

Question # 11

0.1 kg mass will be equivalent to the energy

9 x 10¹⁵J A
5 x 10⁸J B
6 x 10¹⁶J C
9 x 10^-16J D

Question # 12

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 # 13

The special theory of relativity is based on the

one postulate A
two postulates B
three postulates C
four postulates D

Question # 14

There is no way to detect:

Absolute uniform motion A
Accelerated motion B
State rest C
State of motion D
None of these E

Question # 15

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 # 16

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 # 17

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 # 18

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 # 19

When platinum wire is heated, it appears cherry red at

1600°C A
900°C B
1100°C C
1300°C D

Question # 20

The special theory of relatively treats the problems involving:

Inertial frames of reference A
Non-inertial frames B
Non-accelerated frame C
Botha (A) and (C) D
Both (B) and (C) E

Question # 21

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 # 22

A high temperature, the proportion of shorter wavelengths radiation, emitted by the body

decreases A
first increases then decreases B
increases C
any one of them D

Question # 23

The idea of quantization of energy was proposed by:

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

Question # 24

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 # 25

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 # 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

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 # 28

The concept of direction and position are purely

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

Question # 29

Wave nature of particle was proposed by

Einstein A
Plank B
De-Brogile C
Max well D

Question # 30

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

Sr.#	Question	Answer
1	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
2	The year when A.H. compton was awarded Nobel Prize is:	A. 1923 B. 1927 C. 1931 D. 1935
3	0.1 kg mass will be equivalent to the energy	A. 9 x 10¹⁵J B. 5 x 10⁸J C. 6 x 10¹⁶J D. 9 x 10^-16J
4	There is no way to detect:	A. Absolute uniform motion B. Accelerated motion C. State rest D. State of motion
5	When a platinum wire is heated, it appears orange red at	A. 500°C B. 900°C C. 1100°C D. 1300°C
6	The energy of a photon in a beam of infrared radiation of wavelength 1240 nm is	A. 100 ev B. 10⁶e v C. 10³e v D. 1.0 e v
7	When a platinum wire is heated, it appears white at	A. 1600°C B. 900°C C. 1100°C D. 1300°C
8	The concept of direction and position are purely	A. absolute B. relative C. absolute or relative D. none of these
9	When a position comes close to an electron they annihilate into photons such that	A. each photon has energy 0.51 Me v B. each photon has energy 1.02 Me v C. each photon has energy 0.25 Me v D. none of these
10	According to the Max plank, energy is redialed or absorbed in	A. discrete packets B. continuous waves C. either of them 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