Determine the light pressure exerted on the walls of an electric bulb of power `100 W`. The bulb is made in the form of a sphere of radius `5cm`, its walls reflect `10 %` of the incident light and the rest `90%` of the light is transmitted. Assume that the entire power consumed by the bulb is converted into radiation and transmitted light does not exert any pressure.

A 100 W light bulb is placed at the centre of a spherical chamber of radius 20cm. Assume that 60% of the energy supplied to the bulb is converted into light and that the surface of the chamber is perfectly absorbing. Find the pressure exerted by the light on the surface of the chamber.

A sphere of radius 1.00 cm is placed in the path of a parallel beam of light of large aperture. The intensity of the light is 0.50 W cm^-2 . If the sphere completely absorbs the radiation falling on it, find the force exerted by the light beam on the sphere.

A beam of white light is incident normaly on a plane surface absorbing 70% of the light and reflecting the rest. If the incident beam carries 10 w of power, find the force exerated by it on the surface.

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 , find the force exerted by it on the surface .

A parallel beam of light is incident normally on a plane surface absorbing 40% of the light and reflecting the rest. If the incident beam carries 60 W of power, the force exerted by it on the surface is

A laser beam of power 20W incident normally on a surface. if 25% light is absorbed and rest reflected find magnitude of force experienced by the surface.

How many photons per second does a one watt bulb emit if its efficiency is 10% and the wavelength of light emitted is 500 nm

In a modified Young's double-slit experiment, a monochromatic uniform and parallel beam of light of wavelength 6000 Å and intensity (10//pi) W m^(-2) is incident normally on two circular apertures A and B of radii 0.001 m and 0.002 m, respectively. A perfectly transparent film of thickness 2000 Å and refractive index 1.5 for the wavelength of 6000 Å is placed in front of aperture A (see the figure). Calculate the power (in mW) received at the focal spot F of the lens. Then lens is symmetrically placed with respect to the aperture. Assume that 10% of the power received by each aperture goes in the original direction and is brought to the focal spot.

The number of photons emitted by a 60 W bulb per second, if 10% of the electrical energy supplied to an incandescent light bulb is radiated as visible light, is

About 5% of the power of a 100 W light bulb is converted to visible radiation. What is the average intensity of visible radiation (a) at a distance of 1 m from the bulb? (b) at a distance of 10 m ? Assume that the radiation is esmitted isotropically and neglect reflection.