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WorksheetsElectrical Control Circuit Quiz
Total questions: 25
Worksheet time: 13mins
In a motor control circuit with multiple start/start pushbutton stations, the stop buttons would be connected in ______ and the start buttons would be connected in _______.
Series, parallel
Parallel, Series
Series, Series
Parallel, Parallel
If the circuit in the drawing was operating normally and an overload occurred, then
Both lights would come on
The green light would come on, and the red light would go out.
Both lights would go out
The red light would come on, and the green light would go out.
The essential difference between a magnetic motor starter and a magnetic contactor is that the contactor does not contain:
Shading coils
Holding contacts
Overload relay protection
Horsepower-rated contacts
The rotation of an AC three-phase induction motor may be reversed by interchanging:
The control circuit.
The forward/reverse interlocks
The forward reverse coils.
Any two power lines
Overcurrent protection can be achieved by:
A
B
C
D
Overload protection can be achieved by:
A
B
C
D
If an AC magnetic contactor with a 480V coil was energized with 120V, then most likely the:
Overload relay would trip.
Contactor would not pick up.
Control circuit fuses would blow.
Coil would overheat during normal operation.
When energized by the control circuit, start or stop a control action
A
B
C
D
In a ladder diagram, a dotted line between two coils generally means that the two coils:
Are operated together.
Are mechanically interlocked.
Are electrically interlocked.
Have a common set of contacts.
The _________ PB switch must be connected in parallel with a set of _________ auxiliary contacts on the motor starter to hold the state.
NO Start, NC
NO Start, NO
NC Start, NO
NC Start, NC
The purpose of electrical interlocking in a three-phase reversing AC magnetic motor starter is to:
Ensure that the forward direction of rotation is selected first.
Allow both coils to be energized together.
Prevent both coils from being energized simultaneously.
Maintain the coil circuit after the stop button is released.
The part of a manual AC motor starter which senses motor overload current is the:
High-limit switch
Heater element
Solder-pot assembly
Overload contact
The electrical interlocks in a reversing magnetic starter are:
Normally closed contacts
Normally open contacts
In parallel with the forward and reverse pushbuttons
Controlled by the timing relays necessary for circuit operation.
Referring to the drawing, assuming that fuse C is blown, which pair of points will result in a reading of zero volts when the voltmeter is connected across them?
5,2
5,6
3,6
5,4
To troubleshoot an electrical control circuit, the best drawing to be used would be:
Schematic
Pictorial
Wiring
Raceway
A drawing which shows the relative locations of various components is a:
Wiring diagram
Schematic diagram
Elementary diagram
Ladder diagram
To connect a motor solely for jogging operation, the control circuit will
Use holding contacts.
Connect holding contacts in series with the start button.
Connect holding contacts in parallel with the start button.
Do not use holding contacts.
If the motor starter in the drawing is energized and functioning properly, what should the voltage be across the normally open contact (M)?
Line voltage
Zero voltage
Half of line voltage
Twice line voltage
The electrical interlocks in a reversing magnetic starter are:
Controlled by the timing relays necessary for circuit operation.
In parallel with the forward and reverse pushbuttons
Normally closed contacts
Normally open contacts
If the motor starter in the drawing is energized and functioning properly, what should be the voltage across the N.C contact (M)?
Line voltage
Zero voltage
Half of line voltage
Twice line voltage
NO stands for
Normally Off
Normally ON
Normally Open
Normally Overloaded
Overload protection for motors is achieved by connecting:
Thermal sensing elements in series with the motor
A reset relay in series with the motor
Cartridge fuses in series with the motor
A set of N.C contacts in series with the motor
When connected as a start button in the control circuit of a magnetic starter, which pair of terminals usually are utilized?
1,2
1,4
3,4
3,2
One of the following is an input device.
Motor
Light
Valve
Sensor
For frequently on/Off a motor we use
Relay
Contactor
Switch
Circuit breaker
