Question

10.The resistance of hot filament of the bulb is about 10 times the cold resistance. What will be the resistance of 100 W-220 V lamp, when not in use?

1 point

48 Ω

400 Ω

484 Ω

(d) 48.4 Ω

ji look​

Answer 1

Answer:

Resistance of the tungsten filament when hot, Ro = V^2 / P = 200*200/100 = 400 ohm

Given, Resistance of the tungsten filament when cold, Rc = Ro / 10  

Thus, Rc = 400 / 10 = 40 ohm

The resistance of the tungsten filament when not in use is 40 ohm.

Answer 2

Answer:

40 ohm

Explanation:

Resistance of the tungsten filament when hot, Ro = V^2 / P = 200*200/100 = 400 ohm

Given, Resistance of the tungsten filament when cold, Rc = Ro / 10  

Thus, Rc = 400 / 10 = 40 ohm

The resistance of the tungsten filament when not in use is 40 ohm.