Question

Two rods made of same material having same length and diameter are joined in series. The thermal power dissipated through then is 2W. If they are joined in parallel, the thermal power dissipated under the same conditions on the two ends of the rods, will be -

• A. 16 W
• B. 8 W
• C. 4 W
• D. 2 W

Answer 1

Answer: (B)

8 W

Answer 2

2W = $\frac{T_{1}–T_{2}}{2R}$

t = $\frac{T_{1}–T_{2}}{R/2}$

$\frac{2watt}{\tau}$ = $\frac{T_{1}–T_{2}}{2R}$ × $\frac{R}{2(T_{1}–T_{2})}$

t = 8 watt