Fig. shows a conduction rod of non uniform cross-section. The ends of the rod are maintained at constant temperatures 100°C and 0°C respectively. At steady state, temperatures of P, Q, R and S are T_p, T_Q, T_R and T_s respectively, then:
 

• A

  ${\mathrm{T}}_{\mathrm{p}}-{\mathrm{T}}_{\mathrm{Q}}= {\mathrm{T}}_{\mathrm{R}}-{\mathrm{T}}_{\mathrm{S}}$

• B

  ${\mathrm{T}}_{\mathrm{P}}-{\mathrm{T}}_{\mathrm{Q}}>{\mathrm{T}}_{\mathrm{R}}-{\mathrm{T}}_{\mathrm{S}}$

• C

  ${\mathrm{T}}_{\mathrm{P}}-{\mathrm{T}}_{\mathrm{Q}}<{\mathrm{T}}_{\mathrm{R}}-{\mathrm{T}}_{\mathrm{S}}$

• D

  none of these