A battery, having a constant internal resistance, is connected to a resistor with resistance $250\,\Omega$, as shown. The current in the resistor is $40\,\text{mA}$ for $60\,\text{s}$. Over this interval, $6.0\,\text{J}$ of energy is dissipated in the internal resistance. What are the energy delivered to the external resistor in the $60\,\text{s}$ and the e.m.f. of the battery?
Physics 9702 · AS & A Level · Potential difference and power