Question

For the wave shown in the figure, the distance between points $A$ and $D$ is $12m$. Find the wavelength of the wave.

• A. $12m$
• B. $16m$
• C. $8m$
• D. $4m$

Answer 1

The correct option is C $8m$

In the diagram you can see that points A and C are on two successive crests.

The distance between two successive crests or troughs is known as wavelength$\left(\lambda \right)$ of the wave.

The distance between A and C is one $\lambda$.

The points C and D are on a crest and the immediate next trough respectively.

The distance between C and D is $\frac{\lambda }{2}=0.5\lambda$.

Hence the distance between A and D is =$1.5\lambda$

It is given thatthe distance between A and D is $12m$

$\therefore 12=1.5\lambda$

$\therefore \lambda =\frac{12}{1.5}=8m$

Wavelength of the wave is 8 metres.