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

Question # 1

The idea of quantization of energy was proposed by:

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

Question # 2

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 # 3

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 # 4

The way through which electromagnetic radiations or photons interact with matter depends upon their:

Wavelength A
Frequency B
Energy C
Temperature D
All of these E

Question # 5

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 # 6

From the theory of relativity, momentum p of the photon is related to energy as

p = hfc A
p = hf/c B
p = f(hc,f) C
p = cf/h D

Question # 7

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 # 8

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 # 9

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 # 10

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 # 11

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 # 12

Strictly speaking, the earth is:

An accelerated frame of reference A
A non-inertial frame of reference B
An inertial frame of reference C
^{A non-accelerated frame of reference} D
Both (A) and (B) E

Question # 13

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 # 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

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 # 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

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 # 18

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 # 19

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 # 20

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 # 21

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 # 22

Which of the following phenomenon proves the particle nature of light

interference A
diffraction B
photoelectric effect C
none of these D

Question # 23

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 # 24

The inside cavity of the black body is

painted white A
painted silver B
blackened with soot C
painted red D

Question # 25

S.I. unit of planks constant is

J-s^-1 A
J.s B
J.s^-2 C
J.s² D

Question # 26

An inertial frame is that frame in which

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

Question # 27

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 # 28

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 # 29

Wien's constant is measured in:

Metre per kelviin A
Metre kelvin B
Kelvin per meter C
Joules D
Dynes E

Question # 30

The value of the plank's constant 'h' is given by

1.6 x 10^-19J A
1.67 x 10^-27Kg B
6.63 x 10³⁴Js C
6.63 x 10^-34Js D

Sr.#	Question	Answer
1	Photoelectrons are emitted when ultraviolet light falls on:	A. Casium B. Silver C. Potassium D. Any of these
2	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
3	The special theory of relativity treats problems invoving	A. inertial frame of references B. accelerating frame of references C. both of these D. none of these
4	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	A. 1.66 m B. 1.0 m C. 0.66 m D. 2.66 m
5	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
6	The ratio of energy E to the corresponding frequency (f) of the radiation (emitted or absorbed) is called:	A. Wien's constant B. Stefen's constnat C. Planck's constant D. Boltzmann's constant
7	As the light shines on the metal surface, the electrons are ejected	A. slowly B. instantaneously C. either of these 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	S.I. unit of planks constant is	A. J-s^-1 B. J.s C. J.s^-2 D. J.s²
10	The mass of an object will be doubled at speed	A. 1.6 x 10⁸ms^-1 B. 2.6 X 10⁸ms^-1 C. 2.6 x 10⁷ms^-1 D. 2.6 x 10⁹ms^-1

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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