Question # 1

When low energy photon interact with a metal,which of the following effect is likely to be taken place

Choose an answer

pair production

photoelectric

Compton effect

None of these

Wien's constant is measured in:

Choose an answer

Metre per kelviin

Metre kelvin

Kelvin per meter

Joules

Dynes

Absolute motion cannot be detected

Choose an answer

in its own frame of references

in a different frame of references

both in its frame and different frame of references

none of these

The existence of position was predicted by Dirace in

Choose an answer

1920

1925

1930

1928

The length contraction happens only

Choose an answer

Opposite to the direction of motion

along the direction of motion

perpendicular to the direction of motion

In any direction

At the temperature, a body emits radiation which is principally

Choose an answer

of long wavelengths in the visible region

of long wavelengths in the invisible infrared region

of short wavelength in invisible ultraviolet region

none of these

Which of the following phenomenon proves the particle nature of light

Choose an answer

interference

diffraction

photoelectric effect

none of these

Compton was awarded Nobel prize in physics in

Choose an answer

1921

1923

1925

1927

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)

According to the Max plank, energy is redialed or absorbed in

Choose an answer

discrete packets

continuous waves

either of them

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

The analysis of the distribution of wavelengths of the radiation emitted from a hot body set the foundation of new mechanics, known as

Choose an answer

classical mechanics

Newtonian mechanics

quantum mechanics

statistical mechanics

Electromagnetic radiation or photons interact with matter in

Choose an answer

two distinct ways

three distinct ways

four distinct ways

five distinct ways

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

Choose an answer

500°C

900°C

1100°C

1300°C

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

Choose an answer

p = hfc

p = hf/c

p = f(hc,f)

p = cf/h

The intensity of emitted energy (with wavelength) radiated from a black body at different temperatures was initially measured by:

Choose an answer

Lummer

Planck

Pringsheim

Both (A ) and (B)

Both (A) and (C)

The general theory of relativity treats problems involving

Choose an answer

inertial frame of references

accelerating frame of references

both of these

none of these

The special theory of relativity is based on the

Choose an answer

one postulate

two postulates

three postulates

four postulates

Wave nature of particle was proposed by

Choose an answer

Einstein

Plank

De-Brogile

Max well

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

Choose an answer

photoelectric effect

pair production

Compton effect

uncertainty principle

A particle of mass 5.0 mg moves with a speed of 8.0 m/s. Its de-Brogile wavelength is

Choose an answer

1.66 m

1.66 x 10^-10m

1.66 x 10^-29cm

1.66 x 10^-29m

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

Choose an answer

larger

shorter

equal

none of these

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

Choose an answer

0.5 to 1 m to possible

1 m to 10 m is possible

0.5 to 1 nm is possible

1 to 10 nm is possible

S.I. unit of planks constant is

Choose an answer

J-s^-1

J.s

J.s^-2

J.s²

An electron is accelerated through a potential difference of 50v. its de-Brogile wavelength is

Choose an answer

1.66 x 10^-29m

1.74 x 10^-10cm

17.4 x 10^-6m

1.74 x 10^-10m

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

Choose an answer

0.511 Me v

0.256 Me v

1.02 Me v

0.956 Me v

The whole shape of the black body spectrum for all wavelengths was explained by the formula proposed by

Choose an answer

Max plank

Newton

Einstein

J.J. Thomson

Max plank received the Nobel Prize in physics for his discovery of energy quanta in

Choose an answer

1900

1906

1912

1918

The concept of direction and position are purely

Choose an answer

absolute

relative

absolute or relative

none of these

Practically the quantity v/c is always:

Choose an answer

less than one

Equal to one

Greater then one

all of these

None of these

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

Choose an answer

500 m

500 nm

500 km

500 cm

None of these

More Classes

Other Links

ECAT Pre General Science 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

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

Choose an answer