Q. The frequency of the sinusoidal wave $y = 0.40\cos{\lbrack 2000t + 0.80x\rbrack}$ would be
A) $1000\ \pi\ Hz$
B) $2000\ Hz$
C) $20\ Hz$
D) $\frac{1000}{\pi}Hz$
Explanation
(d) Compare the given equation with $y = a\cos(\omega t + k\phi)$
$\Rightarrow \omega = 2\pi n = 2000 \Rightarrow n = \frac{1000}{\pi}Hz$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.