The resistance of the bulb filament is 100 at a temperature of `100^(@)C`. If its temperature coefficient of resistance be `0.005 per ^(@)C`, its resistance will become ` 200 Omega ` at a temperature

Options

A. `200^(@)C`
B. `500^(@)C`
C. `400^(@)C`
D. `300^(@)C`

Answer

C

Explanation

`R_(2)= R_(1) (1 + alpha (T_(2)-T_(1)))`
`200= 100 (1 + 0.005) (T_(2)-100)`
`T_(2)= 300`