Question

A body of length 1 m having cross-sectional area $0.75\, m^2$ has heat flow through it at the rate of 6000 J/s. Then find the temperature difference if $K = 200Jm^{-2} K^{-1}$.

• A. $20^{\circ}\,C$
• B. $40^{\circ}\,C$
• C. $80^{\circ}\,C$
• D. $100^{\circ}\,C$

Answer 1

Answer: (B)

The rate of heat flow, $\frac{Q}{t}=\frac{KA\Delta\theta}{I}$ $\Rightarrow 6000=\frac{200\times0.75\times\Delta\theta}{1}$ $\Delta\theta=\frac{6000\times1}{200\times0.75} \, =\, 40^{\circ}\,C$