Question

In a ripple tank when one pulse is sent every tenth of a second , the distance between consecutive pulses is $30mm$. In the same depth of water pulses are produced at half second intervals. What is the new distance between consecutive pulses ?

• A. $0.67mm$
• B. $6.0mm$
• C. $150mm$
• D. $600mm$

Answer 1

Answer: (C)

$150mm$

At the same depth under water velocity of sound will be same
$\therefore$ $v_1=v_2$
$\Rightarrow$ $\frac{{\lambda }_1}{T_1}=\frac{{\lambda }_2}{T_2}$
$\therefore$ ${\lambda }_2=\frac{T_2}{T_1}{\lambda }_1$
$=\frac{1/2}{1/10}\times 30=150mm$