Question # 1

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

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thermoionic electrons

free electrons

photoelectrons

slow electrons

The special theory of relatively treats the problems involving:

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Inertial frames of reference

Non-inertial frames

Non-accelerated frame

Botha (A) and (C)

Both (B) and (C)

Compton shift refers to:

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Photon

Meson

Proton

Positron

Both (B) and (D)

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

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

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

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500°C

900°C

1100°C

1300°C

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

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Max plank

Newton

Einstein

J.J. Thomson

The concept of direction and position are purely

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absolute

relative

absolute or relative

none of these

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

The photon of radio-waves has energy of about

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1 Me V

1 Ke v

10^-10e v

10¹⁰e v

Practically the quantity v/c is always:

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less than one

Equal to one

Greater then one

all of these

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)

There is certain frequency below which no electrons are emitted from the metal surface, this frequency is known as

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maximum frequency

minimum frequency

threshold frequency

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

If a body reaches a speed equal to the speed of light, then its mass will became

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zero

very small

infinity

none of these

A particle having mass and charge equal to that of an electron is called:

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Proton

Positron

Pion

Pi-meson

Both (C) and (D)

The inside cavity of the black body is

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painted white

painted silver

blackened with soot

painted red

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

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1.66 m

1.66 x 10^-10m

1.66 x 10^-29cm

1.66 x 10^-29m

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

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Physical

Chemical

Biological

All of these

None of these

the symbol to be used in relativity problems denotes:

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Dilated time

Proper time

Life time

Half time

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

A black body is

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an ideal absorber

an ideal radiator

both of them

none of them

The length contraction happens only

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Opposite to the direction of motion

along the direction of motion

perpendicular to the direction of motion

In any direction

Compton studied the scattering of x-rays by loosely bound electrons from:

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NaCl crystal

Graphite crystal

Zirconia

Copper crystal

None of these

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

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larger

shorter

equal

none of these

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

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1900

1906

1912

1918

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

As the light shines on the metal surface, the electrons are ejected

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slowly

instantaneously

either of these

none of these

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

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ON switch

off switch

function switch

none of these

Max plank founded a mathematical model resulting in an equation that describes the shape of observed black body radiation curves exactly, in

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1890

1895

1900

1905

There is no way to detect:

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Absolute uniform motion

Accelerated motion

State rest

State of motion

None of these

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