KCET 2025 Physics Paper

The sinusoidal voltage from an AC generator at any instant is represented by the equation
V=311sin‌314t
To determine the root mean square (rms) value of the voltage, we use the formula for the rms value of a sinusoidal voltage:
Vrms=‌

V0

√2

=‌

311

√2

=220V
Here, V0=311V is the peak voltage.
To find the frequency, we use the relationship between angular frequency (ω) and frequency (f) :
ω=2πf
Given ω=314, we set:
314=2πf
Solving for f, we find:
f=‌

314

2π

≈50‌Hz
Thus, the rms value of the voltage is 220 V , and the frequency is 50 Hz .