KEAM 2011 Physics and Chemistry Paper

The instantaneous voltage is E=100‌sin(100t) volt ... (i)
Compare it with E=E0‌sin(ωt) volt
We get E0=100‌volt,ω=100rads−1
The rms value of voltage is Erms=‌

E0

√2

=‌

100

√2

volt =70.7V
The instantaneous value of current is I=100‌sin(100t+‌

π

3

)‌m‌A
Compare it with I=I0‌sin(ωt+φ)
We get, I0=100mA,ω=100rads−1
The rms value of current is
Irms=‌

I0

√2

=‌

100

√2

mA=70.7mA