The temperature coefficient of resistance of a wire is 0.00125 per `.^oC`. At 300K, its resistance is 1 `Omega`. The resistance of the wire will be 2 `Omega` at

Answer

`1127 K`

Explanation

Here `alpha = 0.00125^(@)C^(-1)`
`t_(1) = 300 K= 300 - 273 = 27^(@)C`
`R_(27) = R_(0) (1 + alpha xx 27)`
and `R_(t) = R_(0) ( 1+alpha xx t)`
or `1 = R_(0) (1+ alpha xx 27) and 2 = R_(0) (1+ alpha t)`
`:. (2)/(1) (1+alpha t)/(1+alpha xx 27) or 1+ alpha t = 2+ 54 alpha`
or `t = (1+ 54 alpha)/(alpha) = (1+ 54 xx 0.00125)/(0.00125) = 854 ^(@)C`
`= 854 + 273 = 1127 K`