Question

There are three 20.0 Ohm resistors connected in series across a 120 V generator. What is the current in the circuit?
120 A
20 A
720 A
2 A

Answer 1

To determine the current in a circuit with resistors in series, we first need to calculate the total resistance of the circuit and then apply Ohm's Law.

1. **Calculate the total resistance:**
Since the resistors are in series, their resistances add up.
\[
R_{\text{total}} = R_1 + R_2 + R_3 = 20.0\, \Omega + 20.0\, \Omega + 20.0\, \Omega = 60.0\, \Omega
\]

2. **Use Ohm's Law to find the current:**
Ohm's Law is given by the formula:
\[
I = \frac{V}{R}
\]
where \(I\) is the current, \(V\) is the voltage, and \(R\) is the resistance.
Given \(V = 120\, V\) and \(R = 60.0\, \Omega\), we can substitute these values into the formula:
\[
I = \frac{120\, V}{60.0\, \Omega} = 2\, A
\]

Thus, the current in the circuit is **2 A**.