A combined circuit has two resistors in parallel (34.0 ohms and 41.0 ohms) and another in series (15.0 ohms). If the power source is 9.0 volts, what will the current be? . A.. 0.054 amps. B.. 33.6 amps. C.. 0.27 amps. D.. 0.48 amps. E.. 0.60 amps.

Verified Answer :

If the power source is 9.0 volts, the current will
be 0.27 amps. The correct answer between all the
choices given is the third choice or letter C. I am hoping that this answer has
satisfied your query and it will be able to help you, and if you would like,
feel free to ask another question.

Answer : Current, I = 0.27 amps

Explanation :

Given that,

Two resistors R₁ = 34.0 ohms and R₂ = 41.0 ohms in parallel and another resistor R₃ = 15.0 ohms in series.

The voltage across them is 9 volts.

Taking the equivalent of R₁ and R₂ :

\(\dfrac{1}{R_{eq}}=\dfrac{1}{R_1}+\dfrac{1}{R_2}\)

\(\dfrac{1}{R_{eq}}=\dfrac{1}{34}+\dfrac{1}{41}\)

\(R_{eq}=18.58\ \Omega\)

Now, Taking series combination of \(R_{eq}\) and R₃

So, \(R'_{f}=33.58\ \Omega\)

Using Ohm/s law :

\(V=IR\)

\(I=\dfrac{V}{R}\)

\(I=\dfrac{9\ V}{33.58\ \Omega}\)

I = 0.268 A

or

I = 0.27 amps

So, the correct option is (C) " 0.27 amps "