The potential difference V and the current I flowing through an instrument in an AC circuit are given by V=5cosωtvolt,I=2sinωtAmp . The power dissipated in the circuit is
The voltage can be written as,
V=5(sinωt+π2)
The angle between the voltage and the current is 90∘.
The power dissipated in the circuit is given as,
P=VrmsIrmscosϕ
=VrmsIrmscos90∘
=0
Thus, the power dissipated in the circuit is 0.