A Battery Has an Emf $\varepsilon = 78.0 \mathrm {~V}$ And an Internal Resistance

Multiple Choice

A battery has an emf $\varepsilon = 78.0 \mathrm {~V}$ and an internal resistance $r = 4.0 \Omega$ , as shown in the figure. A current of $4.7 \mathrm {~A}$ is drawn from the battery when a resistor $R$ is connected across the terminals a and $b$ . The power dissipated by the resistor $R$ is closest to

A) $300 \mathrm {~W}$ .
B) $280 \mathrm {~W}$
C) $320 \mathrm {~W}$ .
D) $370 \mathrm {~W}$ .
E) $340 \mathrm {~W}$ .