Question

Four identical rods of same material are joined at ends so as to form a square. If the temperature difference at the ends of a diagonal is 100${}^o$C, then the temperature difference across the ends of another diagonal will be

• A. $0^{o}C$
• B. ${25}^{o}C$
• C. ${50}^{o}C$
• D. ${100}^{o}C$

Answer 1

Answer: (A)

$0^{o}C$

Four identical rods A, B, C, D which having AC & BD as a diagonal point.

Let the temperature at $A=T^{0}C$

Therefore, temperature at $C={t+100}^{0}C$

Heat is conducted from A to C via B or D. B & D lies midway along with the passing of heat conduction through ABC and ADC respectively.

Hence, temperature of $B=\frac{t+(t+100)}{2}={t+50}^{0}C$

similarly,temperature of $D=\frac{t+(t+100)}{2}={t+50}^{0}C$

So, the difference of temperature between diagonal $BD=0$