Question # 1

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)

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

Wien's constant is measured in:

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Metre per kelviin

Metre kelvin

Kelvin per meter

Joules

Dynes

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

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slowly

instantaneously

either of these

none of these

The energy of the 4th orbit in hydrogen atom is

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2.5 ev

- 3.5 ev

-0.85 ev

-13.6 ev

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

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

The inside cavity of the black body is

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painted white

painted silver

blackened with soot

painted red

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

A bar 1.0 m in length and located along x-axix moves with a speed of 0.75 c with respect to a stationary observer. The length of the bar as measured by the stationary observer is

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1.66 m

1.0 m

0.66 m

2.66 m

The Stephen-Boltzmann law for the black body radiation is given by

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E = T²

E = -T²

E = T⁴

E = -T⁴

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

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500°C

900°C

1100°C

1300°C

When a position comes close to an electron they annihilate into photons such that

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each photon has energy 0.51 Me v

each photon has energy 1.02 Me v

each photon has energy 0.25 Me v

none of these

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

Which one of the following physical quantities changes with relativistic speed

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Length

Mass

Time

All of the above

The emission of electrons from a metal surface when exposed to light of suitable frequency is called the

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pair production

Compton effect

photoelectric effect

relativity

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