If the rms current in a 50 Hz ac circuit is 5 A, the value of the current 1/300 seconds after its value becomes zero is

Question

Philoid · Accepted Answer

Given,
rms current,
Frequency,
Note that at t = 0, .

Now,

Also,
Angular frequency,

Now, the current can be represented as some cosine or sine function. Let us choose the sine function.
We know that,

where ϕ is a phase constant.

Now, substituting

Hence, we have

Now, at t = 1/300 s,

Hence, the correct answer is (b)