Question

Two rods of same length have their ends maintained at same temperature. If s1s1 and s2s2 are the cross-sectional area, k1k1 and k2k2 their thermal conductivities, c1c1 and c2c2 their heat capacities,11 and 22 their densities the condition for the rate of flow of heat to be the same in the rods will be

Answer 1

Answer:

Given:

For rod 1

Cross-sectional area =A1

Specific Heat =S1

Temperaturedifference between the ends of the rod =T1−T2

Thermal Conductivity =K1

For rod 2:

 Cross-sectional area =A2

Specific Heat =S2

Temperature difference at ends of the rod =T1−T2

Thermal Conductivity =K2

By Fourier's law of heat conduction:

For 1st rod

dtdQ1=−K1LA1dT

For 2nd rod:

dtdQ2=−K2LA2dT

The rate of heat transfer is same;

Thus,

−K1LA1dT=−K2LA2dT

or

K1A1=K2