The graph of pressure (P) against the reciprocal of the volume (I/V) in Boyles's law is a?

What quantity of heat is required to convert 20 g of ice at 0 ºC to water at the same temperature? (Specific latent heat of ice = 336 Jg\(^{-1}\))

A train of mass 1600 kg attains a speed of 25 ms\(^{-1}\) in 20 seconds. The power developed in the engine is?

The main factor which affects the speed of sound wave is the?

A semiconductor is formed by?