Question

A and B are two points on a uniform metal ring whose centre is O. The angle AOB = q. A and B are maintained at two different constant temperatures. When q = 180⁰ , the rate of total heat flow from A to B is 1.2 W. When q = 90⁰, this rate will be –

• A. 0.6 watt
• B. 0.9 watt
• C. 1.6 watt
• D. 1.8 watt

Answer 1

Answer: (C)

1.6 watt

Answer 2

1.2 = $\frac{KA(T_{1}–T_{2})}{R/4}$

t = $\frac{KA(T_{1}–T_{2})}{\frac{R}{4} + \frac{3R}{4}}$

t = 1.6 watt.