The diagram shows two equal resistors connected in parallel. What is the equivalent resistance at the terminals?

NASCLA Electrical exam practice question · Electrical Theory & Principles

The diagram shows two equal resistors connected in parallel. What is the equivalent resistance at the terminals?

A400 ohms
B20 ohms
10 ohms
D40 ohms

Why C is correct

Two equal resistances in parallel produce half the resistance of either branch, so the equivalent is 10 ohms. The best answer is therefore “10 ohms.” The other choices either address a different system, rely on an unsafe shortcut, or make a conclusion not supported by the stated facts.

Practice 11 more Electrical Theory & Principles questions

Timed mock exams, a wrong book and flashcards — one subscription covers every contractor exam line.

Start studying free

The control schematic shows the source voltage and total loop resistance. What current should the ammeter indicate?
On a single-family remodel during plan review, a single-phase resistive load draws 10 amperes at 240 volts; what is its power?
Using the transformer data shown, what secondary voltage is expected for an ideal transformer?
Three resistors of 4, 6, and 10 ohms are connected in series. What is total resistance?
An ideal transformer steps voltage down by a factor of four. What happens to secondary current for the same apparent power?

The diagram shows two equal resistors connected in parallel. What is the equivalent resistance at the terminals?

The diagram shows two equal resistors connected in parallel. What is the equivalent resistance at the terminals?

More Electrical Theory & Principles questions