Concepts Of Physics MCQ Edition [Volume 2]PhysicsElectric Current in Conductors
At t = 0 , a capacitance C , a resistance R , and an emf E are connected in series. Determine the maximum value of the power delivered by the battery.
Options
- AE ^2 R
- BE ^2 4R
- C2 E ^2 R
- DE ^2 2R
Correct answer
A. E ^2 R
Step-by-step solution
The current in a series RC circuit as a function of time is given by: I(t) = E R e^ -t/RC The power delivered by the battery is the product of its emf and the current flowing through the circuit: P(t) = E I(t) = E ^2 R e^ -t/RC Since the exponential term e^ -t/RC is a decreasing function of time for t 0 , the power delivered by the battery is maximum at the initial moment, t = 0 . Substituting t = 0 into the power equation: P_ max = E ^2 R e⁰ = E ^2 R