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

Question # 1

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

Question # 2

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 # 3

The energy of the 4th orbit in hydrogen atom is

2.5 ev A
- 3.5 ev B
-0.85 ev C
-13.6 ev D

Question # 4

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 # 5

With the help of 50 K v electron microscope, a resolution of

0.5 to 1 m to possible A
1 m to 10 m is possible B
0.5 to 1 nm is possible C
1 to 10 nm is possible D

Question # 6

A photon is considered to have

Momentum A
Energy B
Wavelength C
All of the above D

Question # 7

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 # 8

The idea of quantization of energy was proposed by:

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

Question # 9

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 # 10

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 # 11

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 # 12

When a platinum wire is heated, it appears yellow at

1600°C A
900°C B
1100°C C
1300°C D

Question # 13

In process of annihilation of matter, the two photons produced move in opposite direction to converse

momentum A
charge B
energy C
mass 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

The ratio of energy E to the corresponding frequency (f) of the radiation (emitted or absorbed) is called:

Wien's constant A
Stefen's constnat B
Planck's constant C
Boltzmann's constant D
None of these E

Question # 16

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 # 17

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

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

Question # 18

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 # 19

The emission of electrons from a metal surface when exposed to light of suitable frequency is called the

pair production A
Compton effect B
photoelectric effect C
relativity D

Question # 20

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 # 21

Compton shift refers to:

Photon A
Meson B
Proton C
Positron D
Both (B) and (D) E

Question # 22

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 # 23

The value of the Stephen's constant for black body radiations is given by

5.6 x 10⁸Wm^-2K^-4 A
5.67 x 10^-8Wm^-2K^-4 B
2.9 x 10^-3mK C
2.9 x 10³mK D

Question # 24

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 # 25

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 # 26

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 # 27

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 # 28

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 # 29

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 # 30

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

500°C A
900°C B
1100°C C
1300°C D

Sr.#	Question	Answer
1	The location and speed anywhere on earth can now be determined using relativistic effects by NAVISTAR to an accuracy of	A. 2 cm/s B. 20 cm/s C. 200 cm/s D. 2000 cm/s
2	The Einstein's changes in length, mass and time are not observed in common life because	A. We dont observer then seriously B. The masses are too large C. Their speed is too small than the speed of right D. All of the above
3	A high temperature, the proportion of shorter wavelengths radiation, emitted by the body	A. decreases B. first increases then decreases C. increases D. any one of them
4	The unit of work function is:	A. Joule B. Electron volt C. That of threshold frequency D. Both (A) and (B)
5	A particle having mass and charge equal to that of an electron is called:	A. Proton B. Positron C. Pion D. Pi-meson
6	Wave nature of particle was proposed by	A. Einstein B. Plank C. De-Brogile D. Max well
7	The energy of photon 'E' is proported to	A. The magnetic field H B. The electric field E C. Both the electric and magnetic field H and E D. Frequency
8	When platinum wire is heated, then at the temperature of 500 ^oC, it becomes:	A. Yellow B. Orange red C. Dull red D. White
9	The year when A.H. compton was awarded Nobel Prize is:	A. 1923 B. 1927 C. 1931 D. 1935
10	When monochromatic light is allowed to fall on cathode, it begins to emit electrons, these electrons are called	A. thermoionic electrons B. free electrons C. photoelectrons D. slow electrons

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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