Q. A pulse of sound wave travels a distnce l in helium gas in time T at a particular temperature. If at the same temp. a pulse of sound wave is propagated in oxygen gas, it will cover the same distance l in time---------(Ans:3T)

Q.A transverse wave y=0.05sin(20x-50t) in meters,is propagating along +ve X-axis on a string. A light insect starts crawling on the string with the velocityof 5 cm/s at t=0 along +ve X-axis from a point where x=5cms. After 5 sec the difference in the phase of its position is:-------------                                                                                        (Ans:-245 pi)