What is the minimal resistance of a 100 W light bulb designed to be used in a 120 V circuit?
Answer
12.0 Ω
144 Ω
1.2 Ω
0.83 Ω
minimal, or nominal?
Sine I = P/E, what's 100/120 ?
P = E^2/R = 100W.
120^2/R = 100
R = 144 Ohms
To find the minimal resistance, we can use Ohm's law, which states that the resistance (R) of a circuit is equal to the voltage (V) divided by the current (I).
First, we need to find the current (I) using the power (P) and the voltage (V) of the circuit. The power is given as 100 W and the voltage is given as 120 V.
From the equation P = IV, we can rearrange it to I = P/V. Inserting the values, we get I = 100 W / 120 V = 0.833 A.
Now, we can use Ohm's law to find the resistance (R). Rearranging the equation R = V/I, we get R = 120 V / 0.833 A = 144 Ω.
Therefore, the minimal resistance of the 100 W light bulb designed to be used in a 120 V circuit is 144 Ω.