(d) $n_{1}C_{v}\mathrm{\Delta}T_{1} = n_{2}C_{v}\mathrm{\Delta}T_{2}$ $10 \times (T - 10) = 20(20 - T)$ $T - 10 = 40 - 2T$ $3T = 50 \Rightarrow T = 16.6℃$
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.