Question

A pulse is travelling on a stretched string fixed at one end with velocity $2\text{cm/s}$ as shown in the figure. At $t=0\text{s}$, center of pulse is $4\text{cm}$ apart from the fixed end. The shape of string at $t=2\text{s}$ is

• A.
• B.
• C.
• D.

Answer 1

The correct option is C

At $t=0\text{s}$


At $t=2\text{s}$, distance travelled by wave,
$d=v\times t=2\times 2=4\text{cm}$


As reflection takes place from fixed end, therefore there will be inversion of pulse after reflection. So, half erect and half inverted pulse results into zero amplitude pulse.
Therefore, option $\left(c\right)$ is correct.