Question

Two waves represented by $y_1=asin\omega t$ and $y_2=asin(\omega t+\varphi )$ and $\varphi =\frac{\pi }{2}$ are superposed at any point at a particular instant. The resultant amplitude is

• A. $a$
• B. $4a$
• C. $\sqrt{2}a$
• D. $zero$

Answer 1

Answer: (C)

$\sqrt{2}a$

Since the angle between them is $90$, so $cos{90}^0=0$

So, $R=\sqrt{a^2+a^2}=\sqrt{2}a$