Question

The two ends of a metal rod are maintained at temperatures $100 \,{}^\circ C$ and $110 \,{}^\circ C$ . The rate of heat flow in the rod is found to be $4.0 \, \text{J s}^{- 1}$ . If the ends are maintained at temperatures $200 \,{}^\circ C$ and $210 \,{}^\circ C$ , the rate of heat flow will be:

• A. $44.0\text{J s}^{- 1}$
• B. $16.8\text{ J s}^{- 1}$
• C. $8.0\text{ J s}^{- 1}$
• D. $4.0\text{ J s}^{- 1}$

Answer 1

Answer: (D)

In case I, temperature difference between the ends of rod is $=110-100=10^{o}C$
In case II, temperature difference between the ends of rod is $=210-200=10^{o}C$
Hence, in both the case temperature difference are same i.e. $10^{o}C$
$\therefore $ Rate of heat flow is also $4Js^{- 1}$ in both the cases.