Physics Past Questions and Answers

An open pipe closed at one end produces its first fundamental note. If the velocity of sound in air is P and t the length of the pipe, the frequency of the note is

On a fairly cool rainy day when the temperature is 20^oC, the length of a steel railroad track is 20m. What will be its length on a hot a dry day when the temperature is 40^oC?
[coefficient of linear expansion of steel = 11 x 10^-6K^-1]

If an object is placed between two parallel plane mirrors with their reflecting surfaces facing each other, how many images of the object will be formed?

The phenomenon where by the water droplets in the atmosphere combines with dust particles in the air to reduce visibility is

At what position will an object be placed in front of a concave mirror in order to obtain an image at infinity?