Q. The wave described by y = 0.25 sin(10πx − 2πt), where x and y are in metres and t in seconds, is a wave travelling along the
A) −ve x direction with amplitude 0.25 m and wavelength λ = 0.2 m
B) −ve x direction with frequency 1 Hz
C) +ve x direction with frequency π Hz and wavelength λ = 0.2 m
D) +ve x direction with frequency 1 Hz and wavelength λ = 0.2 m
Explanation
[Solution from source] Compare with y = A sin(kx − ωt): k = 10π gives λ = 2π/k = 0.2 m, and ω = 2π gives f = 1 Hz. The minus sign between the kx and ωt terms means the wave moves along +x. Reading ω = 2π as 'frequency π Hz' confuses ω with 2πf. Answer (4).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.