WorksheetsMidterm Exam ELMEC 1110
Total questions: 10
Worksheet time: 5mins
The green push button is usually used along with its __________ contact as a __________ push button.
NO contact; stop
NO contact; start
NC contact; stop
NC contact; start
How does a reversing starter reverse the direction of rotation of a three-phase motor?
By reversing the polarity of the phases.
By interchanging any two phases to the motor.
By opening one of the 3 contacts.
By adding resistors in parallel.
TRUE/FALSE. Write 'T' if the statement is true and 'F' if the statement is false. The Cam Switch module has overload relay built in.
True
False
How do bimetallic overload relays operate?
Sensors measure the strength of the magnetic field around the power line.
Metal alloys melt as heat goes up with the current rise.
Heat goes up as the current rises, causing bimetal strips to bend.
Bimetal strips are actuated by radio-frequency signals.
What is the main difference between circuit breakers and fuses?
Fuses may be reset, circuit breakers have to be replaced.
Fuses open circuits when the current is too high.
Circuit breakers open circuits when the current is too high.
Fuses have to be replaced; circuit breakers may be reset.
What is motor inrush current?
A brief spike of current when the motor is starting.
The current drawn by a motor at steady state.
The current that is converted into heat.
The current that is converted into motion.
What is the name of the coil of wire around a soft iron core used to operate magnetic contactors and relays?
Lever
Plunger
Solenoid
Drum
Which of the following control devices does not hold its state if you let go?
Cam switch
Selector switch
Toggle switch
Push button
Which diagram represents the circuit as it appears physically?
Wiring diagram
Schematic Diagram
One-line diagram
Elementary Diagram
Which of the following control devices can be used for three-wire control?
Toggle switch
Float switch
Selector switch
Push button
