625 NEIEP
What is the unit of inductance ?
Henry
If a fixed amount of current is flowing in the direction shown in Figure 1 , which of the following
statements is correct when viewed from the end of the wire marked X ?
A magnetic field will be developed which rotates in a counterclockwise rotation .
Which of the following statements is true regarding AC in a purely inductive circuit ?
Current lags voltage by 90 degrees
Which of the following statements describes how an air coil is magnetized ?
As current is increased it eventually reaches saturation .
Which term refers to a material's capacity to transmit magnetic force lines? Permeability
Which of the following core materials would be able to create the strongest magnetic field for a
given applied voltage ?
Permalloy
Of the items listed below , which affects the inductance of a coil ?
Spacing of the windings
Which of the following will increase the inductance of a coil ?
Decrease the spacing between the windings
In an inductive circuit, what effect does counter electromotive force (CEMF) have? It is an
opposing force to the applied voltage which resists changes in circuit current .
At what point is counter electromotive force ( CEMF ) greatest in an inductive circuit ?
When the rate of change for current is maximum
Refer to Figure 2. What is the function of resistor R ,?
Control when the brake is picked up when the BR is closed. Which term describes the
opposition to current flow in AC inductor circuits ?
Inductive reactance
In a 100 volt 60 Hz circuit , what is the total reactance with a 4 Henry inductor in the circuit ?
1507 ohms
What is the name given to the distortion caused on the AC feeders to elevator equipment , due
to static drive controllers ?
Notch effect
When using a megger to check insulation resistance to ground which of the following would be
an acceptable minimum resistance ?
1 Meg ohms
What is the unit of inductance ?
Henry
If a fixed amount of current is flowing in the direction shown in Figure 1 , which of the following
statements is correct when viewed from the end of the wire marked X ?
A magnetic field will be developed which rotates in a counterclockwise rotation .
Which of the following statements is true regarding AC in a purely inductive circuit ?
Current lags voltage by 90 degrees
Which of the following statements describes how an air coil is magnetized ?
As current is increased it eventually reaches saturation .
Which term refers to a material's capacity to transmit magnetic force lines? Permeability
Which of the following core materials would be able to create the strongest magnetic field for a
given applied voltage ?
Permalloy
Of the items listed below , which affects the inductance of a coil ?
Spacing of the windings
Which of the following will increase the inductance of a coil ?
Decrease the spacing between the windings
In an inductive circuit, what effect does counter electromotive force (CEMF) have? It is an
opposing force to the applied voltage which resists changes in circuit current .
At what point is counter electromotive force ( CEMF ) greatest in an inductive circuit ?
When the rate of change for current is maximum
Refer to Figure 2. What is the function of resistor R ,?
Control when the brake is picked up when the BR is closed. Which term describes the
opposition to current flow in AC inductor circuits ?
Inductive reactance
In a 100 volt 60 Hz circuit , what is the total reactance with a 4 Henry inductor in the circuit ?
1507 ohms
What is the name given to the distortion caused on the AC feeders to elevator equipment , due
to static drive controllers ?
Notch effect
When using a megger to check insulation resistance to ground which of the following would be
an acceptable minimum resistance ?
1 Meg ohms
