Question

The temperature coefficient of resistance of wire is $12.5\times {10}^{-4}/C^0$. At 300K the resistance of the wire is 1 ohm. The temperature at which resistance will be 2 ohm is

• A. 1154K
• B. 1100K
• C. 1400K
• D. 1127K

Answer 1

Answer: (B)

1100K

linear temperature coefficient $\alpha =\frac{△R}{R\times △\theta }$

$△R=2\Omega -1\Omega$

$△\theta =T-27$

$\alpha =0.00125$

$0.00125=\frac{1}{1\times (T-27)}⟹T-27=\frac{1}{0.00125}=800⟹T=800+27=827C^0=827+273=1100k$