An ac voltage is described by v(t) = 10 cos (400 πt), find out fr
| An ac voltage is described by v(t) = 10 cos (400 πt), find out frequency and RMS value of voltage.
A. 400 Hz, 7.07V
B. 400 Hz, 14.14V
C. 200 Hz, 14.14V
D. 200 Hz, 7.07V
Please scroll down to see the correct answer and solution guide.
Right Answer is: D
SOLUTION
V(t) = 10 cos (400 π t)
ω = 400 π
⇒ 2 π f = 400 π
⇒ f = 200 Hz
Vm = 10 V
\({V_{rms}} = \frac{{{V_m}}}{{\sqrt 2 }} = \frac{{10}}{{\sqrt 2 }} = 7.07\;V\)