Question

An Aluminium bar is 3.25m long and has a diameter of 25mm. If the temperature difference between the ends is 250°C, find the rate of heat transfer along the bar. (Where the Thermal conductivity for Al is 205W/m°C)

is it 5.67 W, 7.74 W, or 10.5 W?

Answer 1

7.74 W

Step-by-step explanation

The formula for getting the the rate of heat transfer is:

`(Q)/(T)`=
`(KA(T2 - T1) )/(d)`

A = πr² = π×(12.5/1000)²

= 4.908×10⁻⁴m²

Rate of heat transfer =
`(205*4.908×10⁻⁴*250)/(3.25)`

= 7.74 W