Question

The temperature coefficient of resistance for a wire is $0.0012/C^0$. At $300k$ its resistance is ohm. The tempreture at which the resistance becomes $2$ohm is

• A. $1154k$
• B. $1100k$
• C. $1400k$
• D. $300k$

Answer 1

The correct option is D $300k$

The temperature coefficient of resistance for a wire is

$=0.0012/°C$

At $300K$its resistance in $\Omega$

The temperature find at which the resistance becomes $2\Omega$

$R=R_0(1+\alpha t)$

This is the formula of the resistance and temperature.

$\alpha =0.0012/°CT=300KR=R_0(1+0.0012\times 300)\frac{R}{R_0}=1.361.36=(1+0.0012\times T)T=\frac{1.36-1}{0.0012}=300K=27°C$