Kirchhoff's Laws & Measuring Instruments question from MHT CET 2023 (11 May, Shift 2)

Answer: (a)

1. $\frac{6}{3} = \frac{8}{4}$, so the bridge is balanced and G carries no current.
2. Branch PQR has $9\ \Omega$, branch PSR has $12\ \Omega$, in parallel.
3. Current in PQR: $I_1 = 5 \times \frac{12}{9 + 12} = \frac{20}{7}\text{ A}$
4. $V_P - V_Q = 6 \times \frac{20}{7} \approx 17.1\text{ V} \approx 17\text{ V}$
5. So the answer is (a) 17 V.