A common flashlight bulb is rated at 0.30 A and 2.9 V (the values of the current and voltage under operating conditions). If the resistance of the tungsten bulb filament at room temperature (20∘C) is 1.1Ω, what is the temperature of the filament when the bulb is on?

Answer:- T=T0​+α1​(R0​R​−1)=20∘C+(4.5×10−3/K1​)(1.1Ω9.67Ω​−1)=1.8×103∘C

Since a variation in Celsius is equal to a revolution on the Kelvin temperature scale, the
worth of α used in this calculation is not unpredictable with the other units involved. The table has been used.