1) if i1=3 sin ω t and i2= 4 cos ω t, the i3 is A) 5(sinωt+530) B) 5(sinωt+370) C) 5(sinωt−470) D) 5(cosωt+530) Answer: Option AExplanation:From Kirchhoff's current law, i3=i1+i2=3sinωt+4sin(ωt+900) =√32+42+2(3)(4)cos900sin(ωt+ϕ) where tanϕ=4sin9003+4cos900=43 ∴ i3 = 5(sinωt+530)