(a) What is the cause of sensation of sound due to rolling of thunder ? (b) Give the audible range of human ear. (c) What are infrasonic and ultrasonic waves?

(a) The rolling of thunder is due to the successive reflections of the sound from a number of reflecting surfaces, such as the clouds and the land.
(b) 20 Hz to 20,000 Hz.
© Frequencies less than 20 Hz are called infrasonics and those greater than 20 kHz are called ultrasonics.