Motors Final
A device that converts electrical energy into mechanical energy is called a(n)
motor
In a three-phase connection, what is the voltage measured across a single winding?
phase voltage
A delta-wye transformer has its _____ connected as a delta and its _____ connected as a wye.
primary, secondary
______ wire consists of a bundle of small-guage wire..
Stranded
In a three-phase motor, the speed of rotation of the magnetic field is called the _____ speed.
Synchronous
In a motor that has a rotating magnetic field, the speed of that magnetic field is referred to as the _____.
Synchronous speed
Which device is a wiring connector that consists of an insulating body and a clamping device?
Terminal Block
Which of the following conditions will cause a DC series motor to develop into a runaway condition? The armature coil opens, The field coil opens, The physical load which it drives becomes disconnected, All of the above
The physical load which is drives becomes disconnected
Which meter is used to measure difference of potential in a circuit?
Voltmeter
Line current and phase current are the same in the _____ configuration.
WYE
A delta connected set of windings has a phase voltage of 100 V. What is the line voltage?
100 Volts
Three-phase voltages are _____ out of phase with each other.
120 degrees
A delta-delta transformer has a primary voltage of 7200 V and a secondary voltage of 360 V. What is the turns ratio?
20:1
A squirrel-cage rotor induction motor has a synchronous speed of 3600 RPM and an actual rotor speed of 3450 RPM. What is the percent slip?
4.17%
Which meter is used to measure current flow in a circuit?
Ammeter
To reverse the direction of rotation of a three-phase motor, reverse _____
Any two leads
A PWM drive increases the voltage to the motor by __________ the number of pulses it produces during an alternation.
Decreasing
Line voltage and phase voltage are the same in the _____ connection.
Delta
The direction of rotation of a DC motor is changed by reversing the __________.
Field or armature connections
The exact timing value for any position within the timing range must be ____.
Found by trial and error
Does a shunt motor have fair, poor, or good speed regulation
Good
A motor with four stator poles will rotate at __________ a two-pole motor when the applied frequency is 60 Hz.
Half the speed of
Which of the following is used as a visual display to inform the operator of the status of a circuit? Push buttons, Contacts, Indicator Lights, or All answers are correct
Indicator lights
What type of contact is shown here: o-----o I I /\
NCTO on delay
What is the term for a set of relay or switch contacts that are connected (closed) when the device is de-energized?
Normally Closed
What type of timing relay controls the contact shown here: o-----o I I \/
Off delay relay
When calculating the power of a pure resistive load, the voltage and current are in phase with each other and the power factor is _____. One two three or four
One
What type of magnet retains its magnetism after the magnetizing force has been removed from the magnetic field?
Permanent
Which type of diagram is used to illustrate the logic of the interaction of components in an electrical circuit?
Pictorial
Does a DC series motor have fair, poor, or good speed regulation
Poor
The ____________ is a device that prevents accidental reconnection by surrounding an entire electrical plug.
Rotating plug lockout
Which type of diagram is usually a two-dimensional drawing shown from the top and representing the accurate location of all components in a circuit?
Schematic Diagram
The __________ DC motor has the highest starting torque.
Series
A compound motor has _____ field windings.
Series and shunt
When the field winding of a DC motor is connected in parallel with the armature, the motor is called a _____ motor.
Shunt
