2026 WavesPhase difference in a travelling wave Medium Question 1 of 59 in Waves

For a travelling harmonic wave $y(x, t) = 2.0 \cos 2\pi(10t - 0.0080x + 0.35)$, where x and y are in cm and t in s. The phase difference between oscillatory motion of two points separated by a distance of 0.5 m is:

A $8\pi$ rad
B $0.08\pi$ rad
C $0.008\pi$ rad
D $0.8\pi$ rad

The answer is D.

Solution

Comparing with $y = A\cos(\omega t - kx + \phi)$: $k = 2\pi \times 0.0080$ rad/cm $\Delta x = 0.5$ m = 50 cm $\Delta\phi = k\,\Delta x = 2\pi \times 0.008 \times 50$ $\Delta\phi = 0.8\pi$ rad

Waves in past papers

59 questions from this chapter have appeared across 25 exam years.