NEET2012PhysicsAlternating CurrentActual
In an A C circuit, voltage V=V₀ t and inductor L is connected across the circuit. Then the instantaneous power will be
Options
- AV₀^2 2 L t
- B-V₀^2 2 L t
- C-V₀^2 2 L 2 t
- DV₀^2 L 2 t
Correct answer
C. -V₀^2 2 L 2 t
Step-by-step solution
If d I d t is the rate of change of current through inductor L of any instant, then induced emf in the inductor of the same instant is = (- L d I d t ) To maintain the flow of current in the circuit applied voltage must be equal and opposite to the induced voltage. V=- (-L d I d t ) Given, V=V₀ t V₀ t= L d I d t d I d t = V₀ L t or I= -V₀ L t Instantaneous power, P=V I= (V₀ t ) (- V₀ t L ) ( Using (i) & (ii)) = -V₀^2 2 t 2 L