Q. 24

# An aluminium rod and a copper rod of equal length 1.0 m and cross-sectional area 1 cm2 are welded together as shown in figure. One end is kept at a temperature of 20°C and the other at 60°C. Calculate the amount of heat taken out per second from the hot end. Thermal conductivity of aluminium = 200 Wm–1 °C–1 and of copper = 390 Wm–1 °C–1.

Given

Area of cross section

A =1 cm2

=1×10–4 m2

Thermal conductivity of aluminium, KAl = 200 W/m°C

copper, KCu = 390 W/m°C

Now since these rods are connected in parallel,

So heat flowing per second

= qAl + qCu

= KAl × ∆T + KCu ×A× ∆T

= KAl A × (60-20) + KCu A × (60-20)

= 1×10–4 m2 × 40 (200+ 390)

= 2.36 W

Heat drawn in 1 second = 2.36 W

Rate this question :

How useful is this solution?
We strive to provide quality solutions. Please rate us to serve you better.
Related Videos
Work done in Thermodynamic Process43 mins
Try our Mini CourseMaster Important Topics in 7 DaysLearn from IITians, NITians, Doctors & Academic Experts
Dedicated counsellor for each student
24X7 Doubt Resolution
Daily Report Card
Detailed Performance Evaluation
view all courses