Question

1. The 3rd harmonic in a closed pipe is the overtone of the fundamental.   

(a) 1st (b) 2nd (c) 3rd   

2. T/F: In a longitudinal standing wave, a displacement node is a pressure antinode.

3. A place of max/min pressure in a longitudinal standing wave is called a

(a) rarefaction (b) refraction (c) compression (d) pressure node

Answer 1

(1) Since, the second harmonic which is twice of the fundamental frequency, also known as the first overtone. Then the third harmonic in a closed pipe is the second overtone of the fundamental. So, the correct option will be (b) 2nd.

(2) For a longitudinal standing wave, a displacement node is always a pressure antinode. So, this is a true (T) statement.

(3) Since, a place of maximum or minimum pressure in a longitudinal standing wave is called as a pressure node. So, the correct option will be (d) pressure node.