QUESTIONS AND ANSWERS GUARANTEED TO
PASS
◉ What changes continuously around the conductor
when current changes continuousl in AC circuits?
a. Voltage
b. Current
c. Magnetic field
d. Amps. Answer: c Magnetic field
◉ Wires and cables can be classified according
to their:
a. color.
b. size.
c. covering.
d. shape. Answer: c covering.
◉ What kind of starter provides full-voltage starting?
a. Across-the-line
b. Synchronous start
,c. Reactor starter
d. Reduced-voltage start Answer: a Across-the-line
◉ The choice between across-the-line starting
and reduced-voltage starting depends in part
on the size of the: a. starter.
b. wire size.
c. motor.
d. breaker. Answer: c motor.
◉ The most important requirement for good
maintenance of motor starters is:
a. good record keeping.
b. safety of personnel.
c. proper lubrication.
d. clean, dry insulation Answer: c proper lubrication
◉ A reversing starter reverses a three-phase
motor by interchanging:
a. main contacts.
b. two of the line leads.
c. all of the line leads.
,d. control voltage. Answer: b two of the line leads
◉ What kind of protection is provided in a manual across-the-line
three-phase motor control?
a. Overload protection only
b. Ground-fault protection only
c. Short-circuit protection only
d. All of the above Answer: a Overload protection only
◉ Commonly used instead of fuses in industrial
power distribution systems are:
a. disconnects.
b. motor starters.
c. overcurrent relays.
d. circuit breakers. Answer: d circuit breakers.
◉ Distribution protection usually consists of two
elements, protection of both:
a. equipment and circuit.
b. personnel and equipment.
c. wire and control relay.
d. ground fault and current. Answer: a equipment and circuit
, ◉ What is the current in amperes of a 120-volt
circuit with a resistance of 60 ohms, using
Ohm's Law?
a. 0.5 amperes
b. 2.0 amperes
c. 30 amperes
d. 10 amperes Answer: b 2.0 amperes
Solving for I:
I = ER Substituting values into the equation:
I = 120 volts/60 Ohms = 2 amperes
◉ What is the current for a 120-volt circuit with
a 1440-watt load?
a. 0.083 amperes
b. 10 amperes
c. 12 amperes
d. 15 amperes Answer: c 12 amperes
Since P = EI, current can be determined as I = P/E
Substituting values into the equation:
I = 1440 watts /120 volts = 12 amperes