Find the resistance of `240 V - 200` watt electric bulb when glowing. If this resistance is `10` times the resistance at `0^(@)C` and the temperature of the glowing filament is `2000^(@)C`, then find the temperature coefficient of resistance of the filament.

Answer

`200 Omega`

Explanation

`R_(2000) = V^(2)//l^(2)= (240)^(2)//200 = 200 Omega`
Given `R_(2000)= 10 R_(0)`
then ` alpha = (R_(2000) - R_(0)) //R_(0) xx 2000`