ANSWERS TO QUESTIONS Q1. THROUGH Q30.
A1. To remove power from a malfunctioning device; to remove power from a device you
wish to work on and restore power when the work is completed; to turn devices on and off
as the device is needed; to select the function or circuit desired within a device.
A2. Switches, solenoids, and relays.
A4. A manual switch must be turned on or off by a person. An automatic switch turns a
circuit on or off without the action of a person (by using mechanical or electrical
A5. A light switch, an ignition switch, television channel selector, etc.
A6. A thermostat, an automobile distributor, a limit switch, etc.
A7. Multicontact switches make possible the control of more than one circuit or the
selection of one of several possible circuits with a single switch.
A8. Three-pole, single-throw (triple-pole, single-throw)
A9. Single-pole, single-throw, single-break
Single-pole, double-throw, single-break
Single-pole, single-throw, double-break
Single-pole, double-throw, double-break
Double-pole, double-throw, double-break
A10. The type of actuator.
A11. Two-position and three-position.
A12. A momentary switch.
A13. A locked-position switch.
A14. A microswitch.
A15. The maximum current a switch is designed to carry.
A16. The maximum voltage allowable in the circuit in which the switch is installed.
A17. An ohmmeter and a voltmeter.
A18. A voltmeter.
A19. Not acceptable-single throw.
Not acceptable-double break.
Acceptable-choice #2 (different actuator).
Not acceptable-single pole.
Not acceptable-no momentary position.
Acceptable-choice #1 (higher rating).
Not acceptable-locked position incorrect.
Not acceptable-current rating too low.
Not acceptable-voltage rating too low.
A20. The switch operation for smooth and correct operation, the terminals for corrosion,
and the physical condition of the switch.
A21. The magnetic field created in a coil of wire and core will attract a soft iron
plunger when current flows through the coil.
A22. A starter motor and solenoid.
A23. The connections, the plunger, the mechanism that the solenoid actuates, the
energizing voltage, and the coil of the solenoid.
A24. The magnetic field created in a coil of wire will attract aft armature causing a
movement in sets of contacts.
A25. The solenoid provides a mechanical movement of a plunger (a moveable core) while the
core of a relay is fixed.
A26. Control relays and power relays (contactors).
A27. By observing the movement of the contacts if the relay is open or sealed with a
transparent cover. If the relay has an opaque cover, you can "feel" the
operation of the relay by placing your finger on the cover.
A28. The coil should be checked for opens, shorts, or a short to ground; terminal leads
should be checked for charred or burned insulation; the contact surfaces should be checked
for film, carbon, arcing, and contact spacing.
A29. A burnishing tool.
A30. A point bender