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

Try The MCQ's Test For ECAT Pre General Science Physics Chapter 19 Dawn of Modern Physics

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ECAT Pre General Science Physics Chapter 19 Dawn of Modern Physics

00:00
Question # 1

Electromagnetic -radiation means:

Question # 2

The threshold frequency of sodium is 6 x 106MHz. The cut-off wavelength for this metal will be

Question # 3

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

Question # 4

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

Question # 5

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

Question # 6

When a platinum wire is heated, it appears dull red at about

Question # 7

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

Question # 8

The location and speed anywhere on earth can now be determined using relativistic effects by NAVISTAR to an accuracy of

Question # 9

Victor de-Brogile received the Nobel prize in physics in

Question # 10

According to Einstein, with the great increase in the speed of the body, the relativistic mass of the body

Question # 11

According to the special theory of relativity

Question # 12

Position was discovered by Carl Anderson in

Question # 13

Compton derived an expression to find compton shift by applying to the process, the law of conservation of:

Question # 14

When a platinum wire is heated, it appears white at

Question # 15

At the temperature, a body emits radiation which is principally

Question # 16

The mass of an object will be doubled at speed

Question # 17

When monochromatic light is allowed to fall on cathode, it begins to emit electrons, these electrons are called

Question # 18

The special theory of relativity is based on:

Question # 19

If a material object moves with the speed of light 'C' its mass becomes

Question # 20

A non-inertial frame of reference is one, in which

Question # 21

Photoelectric effect takes place with a photon of:

Question # 22

The photoelectric effect, the maximum energy of photoelectrons depends on the

Question # 23

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:

Question # 24

If you are moving at relativistic speed between two points that are a fixed distance apart, then the distance between the two points appers

Question # 25

Photoelectrons are emitted when ultraviolet light falls on:

Question # 26

In order to produce pair production, a photon must have a energy

Question # 27

According to Einstein, with the great increase in the speed of the body the relativistic length of the body

Question # 28

The concept of direction is purely:

Question # 29

Converse of pair production is known as

Question # 30

The energy of the 4th orbit in hydrogen atom is

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ECAT Physics Chapter 19 Important MCQ's

Sr.# Question Answer
1 The speed of a pendulum is measured to be 3.0 s in the inertial reference frame of the pendulum. What is its period measured by an observer moving at a speed of 0.95 c with respect to the pendulum
A. 2.9 s
B. 3.0 s
C. 6.6 s
D. 9.6 s
2 Due to relative motion of observer and the frame of reference of events, time always:
A. Dilates itself
B. Contracts itself
C. Stretches itself
D. Both (A) and (C)
3 The intensity of emitted energy (with wavelength) radiated from a black body at different temperatures was initially measured by:
A. Lummer
B. Planck
C. Pringsheim
D. Both (A ) and (B)
4 Current, voltage, resistance measuring circuit is connected with the galvanometer with the help of switch, known as
A. ON switch
B. off switch
C. function switch
D. none of these
5 the symbol to be used in relativity problems denotes:
A. Dilated time
B. Proper time
C. Life time
D. Half time
6 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
7 According to the electromagnetic wave theory of light, increasing the intensity of incident light should increase the
A. number of photoelectrons
B. size of the photoelectrons
C. charge on photoelectrons
D. K.E of photoelectrons
8 According to the de-Brogile relation, an object of large mass and ordinary speed has
A. very small wavelength
B. very large wavelength
C. very small frequency
D. all of these
9 The value of the Stephen's constant for black body radiations is given by
A. 5.6 x 108Wm-2K-4
B. 5.67 x 10-8Wm-2K-4
C. 2.9 x 10-3mK
D. 2.9 x 103mK
10 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

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