Concepts Of Physics MCQ Edition [Volume 2]PhysicsHeat Transfer
The left end of a copper rod (length = 20 cm , area of cross section = 0.20 cm ^2 ) is kept at 20^ C while the right end is kept at 80^ C . Ignoring any heat loss due to radiation, determine the temperature at a point 11 cm from the left end. Thermal conductivity of copper = 385 W m ⁻¹ ^ C ⁻¹ .
Options
- A33^ C
- B64^ C
- C47^ C
- D53^ C
Correct answer
D. 53^ C
Step-by-step solution
In steady state, the temperature gradient along a uniform rod is constant. The temperature T at a distance x from the left end is given by T = T_L + T_R - T_L L x Substituting the given values T_L = 20^ C , T_R = 80^ C , L = 20 cm , and x = 11 cm T = 20 + 80 - 20 20 11 T = 20 + 60 20 11 T = 20 + 3 11 T = 20 + 33 = 53^ C