Question

An alternating current is given by
`I = i_1 cos omegat + i_2 sin omegat`.
The rms current is given by
A. rms value of current is `5 A`
B. mean value of this current in positive one-half period will be `6/pi`
C. if voltage applied is `V = V_m sin omegat`, then the circuit may contain resistance and capacitance
D. if voltage applied is `V = V_m cos omegat`, then the circuit may contain resistance and inductance only

Answer 1

Correct Answer - C::D
`i=5sin(omegat+53^@)`

`i_0=5A`
`:. i_("rms")=i_0/sqrt2=5/sqrt2A`
Mean value of current in positive half cycle is
`2/pi i_0=(2/pi)(5)=(10/pi)A`
In `V=V_m sin omega t`, current `i=5sin(omegat+53^@)` leads the voltage function. Hence, circuit is capacitive in nature. Same is case with pard `d`.