Question

Standing wave is produced on a string both end fixed. If the standing wave ratio is $3/2$, the percentage of energy transmitted at fixed end is _______?

• A. $4\%$
• B. $96\%$
• C. $16\%$
• D. $20\%$

Answer 1

The correct option is A $4\%$

$\frac{1+\rho }{1-\rho }$=2/3

2+2$\rho$=3-3$\rho$

5$\rho$=1

$\rho$=1/5

ENERGY TRANSMITTED FOR FIRST CASE $E_1$ =1/2M$A^2$ ${\omega }^2$

IN 2ND $E_2$ =1/2M 1/25 $A^2$ ${\omega }^2$

$\frac{E_1}{E_2}$$\times$100=100/25=4%

$\rho$=REFLECTION COFFICIENT

A=IF AMPLITUDE OF INCIDENT WAVE IS A