Question

The same progressive wave is represented by two graphs I and II. Graph I shows how the displacement ' $y$ ' varies with the distance $x$ along the wave at a given time. Graph II shows how $y$ varies with time $t$ at a given point on the wave. The ratio of measurements $AB$ to $CD$, marked on the curves, represents:

• A. wave number k
• B. wave speed v
• C. frequency v
• D. angular frequency $\omega$

Answer 1

Answer: (B)

$AB=\lambda$
$CD=T$
$\frac{AB}{CD}=\frac{\lambda }{T}=f\lambda =v$ i.e., wave speed.