Question

What is the equivalent resistance of the circuit?

Answer 1

Answer:

Option D. 5.45 Ω

Explanation:

From the question given above, the following data were obtained:

Resistance 1 (R₁) = 10 Ω

Resistance 2 (R₂) = 20 Ω

Resistance 3 (R₃) = 30 Ω

Voltage (V) = 120 V

Equivalent resistance (R) =?

The equivalent resistance can be obtained as follow:

1/R = 1/R₁ + 1/R₂ + 1/R₃

1/R = 1/10 + 1/20 + 1/30

Find the least common multiple (lcm) of 10, 20 and 30. The result is 60

Divide 60 by each of the denominators and multiply by their numerators respectively. We have:

1/R = (6 + 3 + 2)/60

1/R = 11/60

Invert

R = 60/11

R = 5.45 Ω

Thus, the equivalent resistance in the circuit is 5.45 Ω