Question

Two resistors of 5.0 and 9.0 are connected in parallel. A 4.0- resistor is then connected in series with the parallel combination. A 6.0-V battery is then connected to the series-parallel combination. What is the current through the 5.0- resistor?

Answer 1

First, we need to find the equivalent resistance of the parallel combination of 5.0 and 9.0 resistors:

1/R = 1/5.0 + 1/9.0

1/R = 0.4 + 0.1111

1/R = 0.5111

R = 1/0.5111

R ≈ 1.955 ohms

The equivalent resistance of the parallel combination is approximately 1.955 ohms.

Next, we need to find the total resistance of the circuit:

R_total = 4.0 + 1.955

R_total = 5.955 ohms

The total resistance of the circuit is approximately 5.955 ohms.

Using Ohm's Law, we can find the current through the circuit:

I = V/R_total

I = 6.0/5.955

I ≈ 1.006 A

The current through the circuit is approximately 1.006 A.

Finally, we can use the current divider rule to find the current through the 5.0-ohm resistor:

I_5 = (R_parallel / (R_parallel + R_series)) * I_total

I_5 = (1.955 / (1.955 + 4.0)) * 1.006

I_5 ≈ 0.383 A

The current through the 5.0-ohm resistor is approximately 0.383 A.