Question

An alternating current is given by
i = i₁ cos⍵t + i₂ sin⍵t
The rms current is given by
(a) i₁ + i₂/√2
(b) |i₁ + i₂|/√2
(c) √i₁² + i₂²/2
(d) √i₁² + i₂²/√2​

Answer 1

Answer:

option c

Explanation:

i=i

1

cosωt+i

2

sinωt

Let i

1

=Isinθ...(1)

i

2

=Icosθ...(2)

i=Isinθcosωt+Icosθsinωt

form equation (1) and (2)

i

1

2

+i

2

2

=I

2

(sin

2

θ+cos

2

θ)

or I=

i

1

2

+i

2

2

I

rms

=

2

I

=

2

i

1

2

+i

2

2