Question

A wave of frequency n = 1000 Hz, propagates at a velocity v = 700 m/sec along x-axis. Phase difference at a given point x during a time interval Dt = 0.5 × 10^–3 sec is –

• A. p
• B. p/2
• C. 3p/2
• D. 2p

Answer 1

Answer: (A)

p

Answer 2

y = A sin (kx – wt)

f = phase = kx – wt

f₁ = kx – wt₁

f₂ = kx – wt₂

Phase : Df = f₂ – f₁ = w(t₁ – t₂)

difference Df = f₂ – f₁ = – w(t₂ – t₁)

Df = – wDt

= – 2p × 10³ × 0.5 × 10^–3

= – 2p × $\frac{1}{2}$= – p