Question

Two travelling waves of equal frequency, with amplitude $4cm$ and $6cm$ respectively, superimpose in a single medium. Find out the range of the amplitude, $A$, of the resultant wave?

• A. $2cm\le A\le 10cm$
• B. $A=5cm$
• C. $A=10cm$
• D. $10cm\le A\le 12cm$
• E. $12cm\le A\le 24cm$

Answer 1

The correct option is A $2cm\le A\le 10cm$

Given : $A_1=4$ cm, $A_2=6cm$

Maximum superimposition: The two waves interfere constructively.

Resultant amplitude $A^{\prime }=A_1+A_2=4+6=10cm$

Minimum superimposition: The two waves interfere destructively.

Resultant amplitude $A^{\prime \prime }=A_2-A_1=6-4=2cm$

Thus range of amplitude is $2cm\le A\le 10cm$