Question

An alternating current from a source is given by i=10sin314t. What is the
effective value of current and frequency of source?

Answer 1

Explanation:

i = i0sinwt

io is the max value of current, so the effective value (rms) will be io/√2 = 10/√2

10/√2 = 7.1 A

Now,

w= 2πf

comparing the eqn given in question,

w= 314

314=2πf

314= 2*3.14f

f = 100/2

thus, frequency will be 50 Hz

Answer 2

Answer:

Effective value of current = 10/(2^0.5) = 7.07 A

Frequency of source = 50 Hz

Explanation:

Given:

Current = i = 10sin314t

on comparing above with i = Isinwt

we get I = 10 and w=314

but we know effective value or rms = I/(2^0.5) = 7.07 A

And w = 2πf = 314

So, f = 314/2π = 50 Hz

where f = frequecny of source = 50 Hz