Question

9. Calculate the total resistance and current in a parallel cir-

cuit with three resistors of 4, 8, and 16 ohms, using any
one of the five methods (calculator suggested). What is
the total resistance and current?
a. 27 ohms (0.4 ampere)
b. 14 ohms (0.8 ampere)
c. 4 ohms (3.0 amperes)
d. 2.3 ohms (5.3 amperes)

Answer 1

d. 2.3 ohms (5.3 amperes)

Step-by-step explanation:

The calculator's 1/x key makes it convenient to calculate parallel resistance.

Req = 1/(1/4 +1/8 +1/16) = 1/(7/16) = 16/7 ≈ 2.3 ohms

This corresponds to answer choice D.

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Additional comment

This problem statement does not tell the applied voltage. The answer choices suggest that it is 12 V. If so, the current is 12/(16/7) = 21/4 = 5.25 amperes.