ASE Electrical Exam - General Electrical System Diagnosis Practice Questions with Answers

How are voltage tests measured? Voltage tests are measured with the test leads of the DMM in parallel to the component or circuit being tested. How do you test applied voltage? 1. In testing applied voltage, the negative or black test lead of the DMM is connected to a battery or chassis ground 2. The positive red lead is then probed near the power source (e.g. a switch or fuse) to determine if the circuit is receiving the proper voltage. What is a handy feature of a DMM? Polarity is not important. 2. If the leads are reversed. the display will simply include a minus sign in front of the reading. How are circuit voltages tested. Take a positive test probe and go from one circuit's power source to the next. Generally, the applied voltages _______________. Should be the same. What is recommended when selecting a DMM to use for testing electronics circuits? 1. It is recommended that it have a 10 megohm or higher impedance. 2.This is necessary to limit the effect the unit might have on accuracy when testing low current flow circuits. 3.The lamp in the test light will draw too much current and this can damage the circuit integrity. What should be done if it is necessary to test for voltage in an energized circuit 1. A convenient way to do this is with a black-probe tool, also know as a "spoon," at various connectors in a particular circuit. 2.This DMM accessory makes it possible to probe into the connector from behind without disconnecting it. Under what conditions should you check current flow in electrical/electronic circuits etc? 1. Current flow tests are used when a circuit is suspected of having higher than normal current flow, such as a dragging blower motor, or a circuit with a low-resistance short to ground.