The temperature coefficient of resistance for a wire is `0.00125^(@)C^(-1)`. At 300 K its resistance is `1Omega`. The temperature at which the resistance becomes `2Omega` is

Options

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

Answer

D

Explanation

`alpha = 0.00125//^(@) C`
`R_(1)/R_(2) =(1 + alphat_(1))/(1 +alphat_(2)) rArr 1/2 =(1 + 0.00125 xx 27)/(1 + 0.00125 xx t)`
`rArr 1 + 0.00125t = 2 + 0.00125 xx 54`
`t(K) = 854 + 273 = 1127 K`