3A Electrical Practice Test Study Guide Complete

3A ELECTRICAL PRACTICE

TEST STUDY GUIDE

COMPLETE

Question 1: What is the primary purpose of a megohmmeter?

Choices:

1) Measure insulation resistance 2) Measure phase rotation 3) Measure light level 4) Measure conductor length

Correct Answer: Measure insulation resistance

Explanation: A megohmmeter applies a DC test voltage and measures very high resistance to evaluate insulation condition.Page 1

Question 2: How should a voltmeter be connected to measure voltage across a

load?

Choices:

1) In series 2) In parallel 3) Only to ground 4) Across the breaker handle

Correct Answer: In parallel

Explanation: Voltage is potential di�erence between two points, so the meter is connected in parallel across those points.

Question 3: How should a clamp ammeter normally be placed to measure load

current?

Choices:

1) Around one current-carrying conductor 2) Around all circuit conductors together 3) Around the grounding electrode only 4) Across two phase terminals

Correct Answer: Around one current-carrying conductor

Explanation: A clamp meter senses the magnetic �eld around current. Clamping one current- carrying conductor prevents �eld cancellation.Page 2

Question 4: What does a live-dead-live test verify?

Choices:

1) The breaker frame size 2) The tester works before and after verifying absence of voltage 3) The conductor insulation color 4) The motor direction

Correct Answer: The tester works before and after verifying absence of voltage

Explanation: Live-dead-live con�rms the tester operates on a known source before and after the de-energized-circuit check.Question 5: A 120 V source is applied to a 24 ohm resistor. What current �ows?

Choices:

1) 2 A

2) 5 A

3) 12 A

4) 24 A

Correct Answer: 5 A

Explanation: Ohm law gives I = V/R = = 5 A.

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