Question # 1

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

Choose an answer

1.6 x 10^-19J

1.67 x 10^-27Kg

6.63 x 10³⁴Js

6.63 x 10^-34Js

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

Choose an answer

Wien's constant

Stefen's constnat

Planck's constant

Boltzmann's constant

None of these

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

Choose an answer

500°C

900°C

1100°C

1300°C

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

Choose an answer

Remains constant

Decreases

Increases to infinity

Reduced to zero

According to the special theory of relativity, a moving clock

Choose an answer

runs faster

runs slower

neither runs faster nor slower

all of these

The energy of a photon is represented by

Choose an answer

h/c²

h/T

hc²

hf/c²

When platinum wire is heated, it appears cherry red at

Choose an answer

1600°C

900°C

1100°C

1300°C

According to the special theory of relativity

Choose an answer

mass and energy are same entities

mass and energy are same entities but interconverible

mass and energy are different entities but interconverible

mass and energy are different entities but non-interconveritble

When a platinum wire is heated, it appears white at

Choose an answer

1600°C

900°C

1100°C

1300°C

Strictly speaking, the earth is:

Choose an answer

An accelerated frame of reference

A non-inertial frame of reference

An inertial frame of reference

^{A non-accelerated frame of reference}

Both (A) and (B)

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:

Choose an answer

Smaller

Lerger

Same

Much larger

None of these

Photoelectric effect takes place with a photon of:

Choose an answer

Very high energy

Very low energy

Low energy

High energy

None of these

S.I. unit of planks constant is

Choose an answer

J-s^-1

J.s

J.s^-2

J.s²

the dilation of time applies to the timing processes which are:

Choose an answer

Physical

Chemical

Biological

All of these

None of these

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

Choose an answer

Equal to its rest mass

Four times of its rest mass

Double of its rest mass

Infinite

More Classes

Other Links

ECAT Physics Chapter 19 Dawn of Modern Physics Online Test MCQs With Answers

Choose an answer

Choose an answer

Choose an answer

Choose an answer

Choose an answer

Choose an answer

Choose an answer

Choose an answer

Choose an answer

Choose an answer

Choose an answer

Choose an answer

Choose an answer

Choose an answer

Choose an answer