1. **State the problem:** We have a circuit with a battery of emf $3.0$ V and internal resistance $2.0\ \Omega$. A resistor $R$ is set to $8.0\ \Omega$. We want to find the voltage reading on the voltmeter across $R$. 2. **Relevant formula:** The total resistance in the circuit is the sum of internal resistance and external resistance: $$R_{total} = R + r = 8.0 + 2.0 = 10.0\ \Omega$$ The current $I$ in the circuit is given by Ohm's law: $$I = \frac{\text{emf}}{R_{total}} = \frac{3.0}{10.0} = 0.3\ \text{A}$$ 3. **Voltage across resistor $R$:** Using Ohm's law again: $$V_R = IR = 0.3 \times 8.0 = 2.4\ \text{V}$$ 4. **Interpretation:** The voltmeter reads the voltage across $R$, so it will read $2.4$ V. **Final answer:** (B) 2.4 V