Question # 1

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

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slowly

instantaneously

either of these

none of these

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

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

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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

The concept of direction and position are purely

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absolute

relative

absolute or relative

none of these

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

Which of the following phenomenon proves the particle nature of light

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interference

diffraction

photoelectric effect

none of these

Newton's law of motion do not hold in

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an accelerated frame of reference

an unaccelerated frame of reference

both of these

none of these

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 year when A.H. compton was awarded Nobel Prize is:

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1923

1927

1931

1935

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

There is no way to detect:

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Absolute uniform motion

Accelerated motion

State rest

State of motion

None of these

Due to relative motion of observer and the frame of reference of events, time always:

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Dilates itself

Contracts itself

Stretches itself

Both (A) and (C)

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)

According to the special theory of relativity, time is

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absolute quantity

not absolute quantity

constant quantity

none of these

Photoelectrons are emitted when ultraviolet light falls on:

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Casium

Silver

Potassium

Any of these

None of these

If A represents linear momentum and c, the velocity of light, then unit of pc in international system of units is:

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Newton

Joule

Joule-Sec

Joule-s^-1

Watt

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

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