List of top Physics Questions on Electromagnetic waves asked in Punjab PMET

A tuning fork of frequency $340\,Hz $ is vibrated just above the tube of $120\,cm $ height. Water is poured slowly in the tube. What is the minimum height of water necessary for the resonance? (speed of sound in air $ =340\,m/s $ )

The difference between the apparent frequency of a source of sound as perceived by the observer during its approach and recession is $2\%$ of the frequency of the source. If the speed of sound in air is $ 300\,ms^{-1}$ , the velocity of the source is

A bomb explodes on the moon. How long will it take for the sound to reach the earth?

Two open organ pipes of length $25\, cm$ and $25.5\, cm$ produce $0.1$ beat/sec. The velocity of sound will be :