question_answer

A string is clamped at both the ends and it is vibrating in its 4th harmonic. The equation of the stationary wave is . The length of the string is : (All quantities are in SI units.)  [JEE Main 9-4-2019 Morning]

A) 20 m

B) 80 m

C) 60 m

D) 40 m

Correct Answer: B

Solution :

[b] 4th harmonic

From equation

Option [b]