Two identical batteries each of emf `E= 2`volt and internal resistance `r=1` ohm are available `t`. produce heat in an external resistance by passing a current through it. What is the maximum power that can be developed across an external resistance `R` using these batteries?

Options

A. `1 W`
B. `2 W`
C. ` 4 W`
D. ` 8 W`

Answer

B

Explanation

Let both the batteries be connected in series. Power output is maximum when external resistance is `2 Omega`. Current in the circuit is ` 4 V//4 Omega = 1 A` and power in the external circuit is `(1)^(2) xx 2 = 2 W`.