1. Magnetic starters can be controlled remotely.
a. True
b. False
2. The magnetic flux produced by the shading coil follows the direction of the flux of the main field.
a. True
b. False
3. Overvoltage produces low coil currents.
a. True
b. False
4. All overload relays must allow some period of time before tripping to allow the motor to start.
a. True
b. False
5. The NEC®
requires that each phase of a motor be protected by an overload relay.
a. True
b. False
Name: Class: Date:
Unit 3 Magnetic Starters
6. Contact surfaces are generally a ____ alloy for better electrical conductivity.
a. mercury b. tungsten
c. copper d. silver
7. ____ overload relays react only to current excesses and are not affected by temperature.
a. Electronic b. Thermal
c. Magnetic d. Solid-state
8. Bimetal strip type overload relays operate on the principle that metals expand and contract with a change of ____.
a. composition b. temperature
c. force d. pressure
9. Two-pole starters are used for ____.
a. single-phase motors b. three-phase motors
c. compound motors d. three-wire AC systems
10. ____ enclosures are constructed of sheet steel and are provided with cover gaskets to exclude dust, lint, dirt, fibers,
and flyings.
a. NEMA 1 b. NEMA 4
c. NEMA 7 d. NEMA 12
Name: Class: Date:
Unit 3 Magnetic Starters