A lamp is rated 240V 60W, calculate the resistance of its filament
Answer Details
To calculate the resistance of the filament in a lamp rated 240V and 60W, we can use Ohm's Law and the formula for electrical power.
Ohm's Law states that resistance (R) is equal to voltage (V) divided by current (I), or R = V/I. The formula for electrical power (P) is given by P = IV, where I is the current in amperes.
First, we can use the formula for electrical power to find the current in the circuit. We know that the lamp is rated 60W and 240V, so we can write:
P = IV
60W = 240V x I
I = 60W / 240V
I = 0.25A
Next, we can use Ohm's Law to find the resistance of the filament:
R = V/I
R = 240V / 0.25A
R = 960Ω
Therefore, the resistance of the filament in the lamp is 960Ω.
The correct answer is (iii) 960Ω.