For a car 40 watt power is utilised for its head lights to show less intensity of light and 50 watt power is utilised to show more intensity of light. In which case the resistance of head lights is more ? Discuss.

The two coherent sources of equal intensity produce maximum intensity of 100 units at a point. If the intensity of one of the sources is reduced by 50% by reducing its width then the intensity of light at the same point will be

(A): With increase of intensity of incident light, photoelectric current also increases. (R): If the intensity of incident radiation is increased, more number of photons strike the metal surface there by liberating more photoelectrons. Then photoelectric current increases.

When two plants L and M were exposed to different light intensities and temperature , they showed changes in their rates of photosynthesis , which have been represented in the following graph. The graph indicates that

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

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