Physics - Heat & Thermo Question with Solution | TestHub

$$PT=\mathrm{constant}\text{ on AB}$$
$$P_B{T}_B=P_A{T}_A$$
$$T_B=300/3=100\mathrm{K}$$
$$P^{2}V=R(PT)=\mathrm{constant}$$
$$P{V}^{1/2}=\mathrm{constant}$$
$$W_{AB}=\frac{R(T_B-T_A)}{1-1/2}$$
$$W_{AB}=\frac{R(100-300)}{1/2}=-400R$$
$$V=\mathrm{constant}\text{ on CA}$$
$$T_C=3T_A=900\mathrm{K}$$
$$\Delta U_{CA}=\frac{3R}{2}(300-900)$$
$$\Delta U_{CA}=-900R$$
$$P=\mathrm{constant}\text{ on BC}$$
$$T_C-T_B=800\mathrm{K}$$
$$W_{BC}=R(800)=800R$$
$$\Delta U_{BC}=\frac{3R}{2}(800)=1200R$$
$$Q_{BC}=800R+1200R=2000R$$
$$\text{Correct options: A, C and D.}$$