To print a photograph from a negative, the time of exposure to light form a lamp placed 0.50 m away is 2.5 sec. How much exposure time is required if the lamp is placed 1.0 m away?

Rukhsar painted the outside of the cabinet of measure 1 m xx 2 m xx 1.5 m .How much surface area did she cover if she painted all except the bottom of the cainet?

A 12 m tall tree is to be photographed with a pin hole camera. It is situated 15 m away from the pin hole. How for should the screen be placed from the pin hole to obtain 12 cm tall image of the tree?

The image of needle placed 45 cm from a lens is formed on a screen placed 90 cm on the otehr side of teh lens.Find the displacement of the image,if the object is moved to 5.0 cm away from the lens.

A Box of 1.00 m^3 is filled with nitrogen at 1.50 atm at 300 K. The box has a hole of an area 0.010 mm^2 . How much time is required for the pressure to reduce by 0.10 atm. If the pressure outside is 1 atm.

A person trying to lose weight (dieter) lifts a 10 kg mass, one thousand times, to a height of 0.5 m each time. Assume that the potential energy lost each time she lowers the massis dissipated:- How much work does she do against thegravitational force ?

Two charges +-10muC are placed 5.0 mm apart. Determine the electric field at a point on the axis of the dipole 15 cm away from its centre 0 on the side of the positive charge