AIIMS 2013 Physics Question Paper for free online practice with solutions

A laser is a highly monochromatic and near perfect parallel beam of light, due to which the beam can be focussed by a converging lens to a very small spot. As the intensity of the beam is too high, it can drill holes through a metal sheet even if the power is 0.2 W. But even a torch-light of 1000 W power cannot drill holes in such a metal sheet, because the light is less intense and the beam is not parallel.