Question

Resistance of the wire is measured as 2 Ω and 3 Ω at 10°C and 30°C respectively. Temperature co-efficient of resistance of the material of the wire is:

• A. 0.033°C–1
• B. –0.033°C–1
• C. 0.011°C–1
• D. 0.055°C–1

Answer 1

Answer: (A)

0.033°C–1

Answer 2

$R_{10} = 2 = R_0(1 + \alpha \times 10)$
$R_{30} = 3 = R_0(1 + \alpha \times 30)$

On solving
$\alpha = \frac{0.033}{1°C}$
\alpha = 0.033^{-}\degree C
So, the correct option is (A): 0.033^{-}\degree C