Question

An ideal inductor, (having initial current zero) a resistor and an ideal battery are connected in series at time `t = 0`. At any time `t`, the battery supplies energy at the rate `P_(B)`, the resistor dissipates energy at the rate `P_(R )` and the inductor stores enegy at the rate `P_(L)`.
A. `P_(B) = P_(R ) + P_(L)` for all times `t`.
B. `P_(R ) lt P_(L)` for all times `t`
C. `P_(R ) lt P_(L)` only near the starting of the circuit.
D. `P_(R ) gt P_(L)` only near the starting of the circuit.

Answer 1

Correct Answer - A::C
By principal of energy conservation.
`P_(B) = P_(R ) + P_(L)`
Near the starting of the circuit
`P_(R ) = i^(2)R` and `P_(L) = L i (di)/(dt)`.
As `(di)/(dt)` has greater the starting of the circuit, `P_(L) gt P_(R )`