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Earn 100

The radiation force due to source of power $P$ on a perfectly reflecting surface will be:

Important Questions on Quantum and Nuclear Physics (HL)

EASY

Physics>Nuclear Physics>Quantum and Nuclear Physics (HL)>Photon and Light

The sound waves after converting into the electric waves are not directly transmitted because:

MEDIUM

Physics>Nuclear Physics>Quantum and Nuclear Physics (HL)>Photon and Light

A radiation of energy

E

falls normally on a perfectly reflecting surface. The momentum transferred to the surface is (

C

= Velocity of light)

MEDIUM

Physics>Nuclear Physics>Quantum and Nuclear Physics (HL)>Photon and Light

What do you understand by the statement, “Electromagnetic waves transport momentum”?

MEDIUM

Physics>Nuclear Physics>Quantum and Nuclear Physics (HL)>Photon and Light

Sun light falls normally on a surface of area

36 {cm}^{2}

and exerts an average force of

7.2 \times 10^{- 9} N

within a time period of

20

minutes. Considering a case of complete absorption, the energy flux of incident light is

EASY

Physics>Nuclear Physics>Quantum and Nuclear Physics (HL)>Photon and Light

The radiation produced by a

100 W

bulb has the following property

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Physics>Nuclear Physics>Quantum and Nuclear Physics (HL)>Photon and Light

A point source of light emits isotropically with a power of $200 W$ . The light is incident normally on a perfectly reflecting circular surface of radius $2 cm$ at a distance of $20 m$ from the source. The force exerted by light on the surface is

Speed of light $c = 3 \times 10^{8} m s^{- 1}$

MEDIUM

Physics>Nuclear Physics>Quantum and Nuclear Physics (HL)>Photon and Light

Light with an energy flux of

25 \times 10^{4} {W m}^{- 2}

falls on a perfectly reflecting surface at normal incidence. If the surface area is

15 {c m}^{2},

the average force exerted on the surface is:

EASY

Physics>Nuclear Physics>Quantum and Nuclear Physics (HL)>Photon and Light

A beam of white light is incident normally on a plane surface absorbing

70 %

of the light and reflecting the rest. If the incident beam carries

10 W

of power, the force exerted by it on the surface is

EASY

Physics>Nuclear Physics>Quantum and Nuclear Physics (HL)>Photon and Light

Light with an energy flux of

120 W {cm}^{- 2}

falls on a normal reflecting surface at normal incidence. Find the average force exerted on the surface in

20 minutes

if the surface has an area of

2

square meter.

MEDIUM

Physics>Nuclear Physics>Quantum and Nuclear Physics (HL)>Photon and Light

The electric field in a plane electromagnetic wave is given by

\vec{E} = 200 \cos [(0.5 \times 10^{3} m^{- 1}) x - (1.5 \times 10^{11} rad s^{- 1}) t] V m^{- 1} \hat{j}

.
If this wave falls normally on a perfectly reflecting surface having an area of

100 {cm}^{2}

. If the radiation pressure exerted by the E.M. wave on the surface during a

10 \min

exposure is

\frac{k}{10^{9}} N m^{- 2}

. Find the value of

k

EASY

Physics>Nuclear Physics>Quantum and Nuclear Physics (HL)>Photon and Light

A beam of light with intensity

10^{- 3} N m^{- 2}

and cross sectional area

20 {cm}^{2}

is incident on a fully reflective surface at angle

45 °

. Then the force exerted by the beam on the surface is

MEDIUM

Physics>Nuclear Physics>Quantum and Nuclear Physics (HL)>Photon and Light

The mass of a hydrogen molecule is

3.32 \times 10^{- 27} kg .

10^{23}

hydrogen molecules strike, per second, a fixed wall of the area

2 {cm}^{2}

at an angle of

45^{o}

to the normal, and rebound elastically with a speed of

10^{3} m s^{- 1},

then the pressure on the wall is nearly:

EASY

Physics>Nuclear Physics>Quantum and Nuclear Physics (HL)>Photon and Light

A light of intensity

12 W m^{- 2}

incidents on a black surface of area

4 {cm}^{2}

. The radiation pressure on the surface is

EASY

Physics>Nuclear Physics>Quantum and Nuclear Physics (HL)>Photon and Light

A laser pointer has an output power of

1 mW

and emits light of wavelength

660 nm

. if the beam from the pointer is incident normally on a perfectly reflecting mirror, the force exerted by the light beam on the mirror will be approximately,

MEDIUM

Physics>Nuclear Physics>Quantum and Nuclear Physics (HL)>Photon and Light

A light bulb of power

100 W

is placed at the centre of a hollow sphere of radius

10 cm .

If the

66 %

of the energy is converted into light, then the pressure exerted by the light on the surface of the sphere will be
(Assume the surface of sphere to be perfectly absorbing)

MEDIUM

Physics>Nuclear Physics>Quantum and Nuclear Physics (HL)>Photon and Light

Sunlight of intensity

50 W m^{- 2}

is incident normally on the surface of a solar panel. Some part of incident energy (

25 %

) is reflected from the surface and the rest is absorbed. The force exerted on

1 m^{2}

surface area will be close to

(c = 3 \times 10^{8} m s^{- 1})

EASY

Physics>Nuclear Physics>Quantum and Nuclear Physics (HL)>Photon and Light

An electromagnetic wave of intensity

I

is incident on a non-reflecting surface. If

C

is the speed of light in free space, then the ratio

\frac{I}{C}

is same as

EASY

Physics>Nuclear Physics>Quantum and Nuclear Physics (HL)>Photon and Light

A plane electromagnetic wave of wave intensity

6 W m^{- 2}

strikes a small mirror of area

40 {cm}^{2}

and is held perpendicular to the approaching wave. The momentum transferred by the wave to the mirror each second will be

MEDIUM

Physics>Nuclear Physics>Quantum and Nuclear Physics (HL)>Photon and Light

100 W

light bulb is placed at the centre of a spherical chamber of radius

0.10 m

. Assume that

66 %

of the energy supplied to the bulb is converted into light and that the surface of chamber is perfectly absorbing. The pressure exerted by the light on the surface of the chamber is

EASY

Physics>Nuclear Physics>Quantum and Nuclear Physics (HL)>Photon and Light

50 W m^{- 2}

is the energy density of sunlight which is normally incident on the surface of a solar panel. One-fourth of the incident energy is reflected from the surface, and the rest is absorbed. The force exerted per square metre surface area will be approximately equal to

(c = 3 \times 10^{8} m s^{- 1})

The radiation force due to source of power P on a perfectly reflecting surface will be:

Important Questions on Quantum and Nuclear Physics (HL)

Learn and Prepare for any exam you want !

The radiation force due to source of power $P$ on a perfectly reflecting surface will be: