AP EAMCET202022 Sep 2020Evening ShiftPhysicsThermal Properties of MatterActual
Cylindrical rod of copper of length 2 ~m and cross-sectional area 2 ~cm ^2 is insulated at its curved surface. The one end of rod is maintained in steam chamber and other is maintained in ice at 0^ C . The thermal conductivity of copper is 386 Js ⁻¹ ~m ⁻¹ ^ C ⁻¹ ). Find the temperature at a point which is at a distance of 120 ~cm from the colder end.
Options
- A80^ C
- B50^ C
- C60^ C
- D70^ C
Correct answer
C. 60^ C
Step-by-step solution
For cylindrical wire, aligned l & =2 ~m , A=2 ~cm ^2=2 10⁻⁴ ~m ^2 ₁ & =100^ C , ₂=0^ C & =? aligned At steady state, temperature gradient of rod remains constant. array ll i.e., & ₁- x₁ = - ₂ x₂ & 100^ - 80 10⁻² = -0^ 120 10⁻² & 100^ - = 80 120 & 100^ - = 2 3 5 3 =100^ & = 100^ 3 5 =60^ C array