Question

question 9 of 25
what is the current in the 30.0 ω resistor?
120.0 v
10.0 ω
20.0 ω
30.0 ω
a. 30.0 a
b. 4.00 a
c. 32.0 a
d. 2.00 a

Explanation:

Step1: Recall Ohm's law

Ohm's law is $I = \frac{V}{R}$, where $I$ is current, $V$ is voltage, and $R$ is resistance. In a parallel - circuit, the voltage across each resistor is the same as the source voltage.

Step2: Identify the voltage across the 30.0 Ω resistor

The voltage across each resistor in a parallel circuit is equal to the source voltage. Here, the source voltage $V = 120.0\ V$, so the voltage across the 30.0 Ω resistor, $V_{30}=120.0\ V$.

Step3: Calculate the current through the 30.0 Ω resistor

Using Ohm's law $I=\frac{V}{R}$, substitute $V = 120.0\ V$ and $R = 30.0\ \Omega$ into the formula. So $I=\frac{120.0\ V}{30.0\ \Omega}=4.00\ A$.

Answer:

B. 4.00 A