Question # 1

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

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500 m

500 nm

500 km

500 cm

None of these

When platinum wire is heated, then at the temperature of 500 ^oC, it becomes:

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Yellow

Orange red

Dull red

White

Cherry red

Position was discovered by Carl Anderson in

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1920

1925

1928

1932

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

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Wavelength

Frequency

Energy

Temperature

All of these

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

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2.9 s

3.0 s

6.6 s

9.6 s

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

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0.511 Me v

0.256 Me v

1.02 Me v

0.956 Me v

Photoelectric effect takes place with a photon of:

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Very high energy

Very low energy

Low energy

High energy

None of these

The nature of radiations emitted by a hot body depends upon its:

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Metarial

Temperature

colour

Volume

Length

Max Planck received the Nobel Prize for his discovery of energy quants in:

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1718 AD

1918 AH

1818 AD

1918 AD

None of these

Strictly speaking, the earth is:

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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)

Davision and Germer performed experiment to verify

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de-Brogile hypothesis

theory of relativity

Newton's law of gravitation

Mass-energy relation

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

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1900

1906

1912

1918

Intensity of light determines the:

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Energy of each photon

Number of photons

Speed of photons

Size of photons

None of these

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

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Equal to its rest mass

Four times of its rest mass

Double of its rest mass

Infinite

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

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particular metal surface

frequency of incident light

both of them

none of them

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

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500°C

900°C

1100°C

1300°C

The special theory of relativity treats problems invoving

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inertial frame of references

accelerating frame of references

both of these

none of these

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

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1.66 x 10^-29m

1.74 x 10^-10cm

17.4 x 10^-6m

1.74 x 10^-10m

G.P. Thomson observer experimentally that electrons and neutrons possess

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particle-like properties

wave-like properties

neither particle nor wave like properties

none of these

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

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discrete packets

continuous waves

either of them

none of these

At the temperature, a body emits radiation which is principally

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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

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

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momentum

charge

energy

mass

The mass 'm' of a body moving at 0.8 c (whose rest mass is mo) becomes

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2 mo

1.67 mo

0.67 mo

2.67 mo

Victor de-Brogile received the Nobel prize in physics in

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1925

1929

1932

1935

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

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1916

1919

1921

1923

Which of the following is not an example of intertial frame

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a body placed on the surface of earth

a body placed in a car moving with uniform velocity

a body placed in a car moving with same acceleration

none of these

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

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2 cm/s

20 cm/s

200 cm/s

2000 cm/s

The general theory of relativity treats problems involving

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inertial frame of references

accelerating frame of references

both of these

none of these

Electromagnetic radiation or photons interact with matter in

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two distinct ways

three distinct ways

four distinct ways

five distinct ways

If the radius of first orbit of hydrogen atom is 0.53° A the radius of second orbit will be

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2.120°A

0.212°A

21.2°A

0.14°

a

In photoelectric effect the energy of ejected electrons depend on

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The frequency

The intensity

Both frequency and intensity

None of these

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