Home
Class 12
PHYSICS
A lamp delivers a luminous flux of 100 w...

A lamp delivers a luminous flux of 100 w to an absorber of area 1 `cm^(2)`. The force due to radiation pressure is

A

`3.3 xx 10^(-4)` N

B

`16.5 xx 10^(-7)`N

C

`3.3 xx 10^(-6)` N

D

`3.3 xx 10^(-7)`N

Text Solution

Verified by Experts

The correct Answer is:
D
`therefore` Force = Rate of change of linear momentum
` F = (dp)/(dt ) = (d)/(dt) ((v)/(c )) = (1)/(c ) (dv)/( dt)`
where, v = electromagnetic wave energy,
or ` F = (I)/(c ) = (100)/(3 xx 10^(8)) = 33.3 xx 10^(-8)` N `" " [ ( because I = 100 " watt, given" )]`
or ` F = 3.3 xx 10^(-7) N`
Promotional Banner

Similar Questions

Explore conceptually related problems

A flashlight of intensity 9 W/ cm^(2) illuminates a perfectly reflective surface of area 300cm^(2) . The average force exerted on the surface due to the incident light photons is

Find the temperatue of an oven if it radiates 8.28 cal per second through an opening, whose area is 6.1 cm^(2) . Assume that the radiation is close to that of a black body.

Radiations of wavelength 200 nm propagating in the form of a parallel beam, fall normally on a plane metallic surface. The intensity of the beam is 5mW and its cross sectional area 1.0mm^(2) . Find the pressure exerted by the radiation on the metallic surface, if the radiation is completely reflected.

A horizontal pipe line carries water in a streamline flow. At a point along the pipe where the cross-sectional area is 10 cm^(2) the velocity of water is 1 m/s and the pressure is 2000 Pa. What is the pressure at another section where the cross-sectional area is 5 cm^(2) ?

Light with energy flux of 18w/cm^(2) falls on a non reflecting surface of area 20cm^(2) at normal incidence the momentum delivered in 30 minutes is