Electronics-Inductors Question and Answer
Electronics-Inductors Question and Answer
11. What does Faraday's law concern?
- a magnetic field in a coil
- a magnetic field cutting a conductor
- a magnetic field hystersis
- a magnetic field in a conductor
12. The polarity of induced voltage while a field is collapsing is:
- independent of the force creating it
- opposite to the force creating it
- identical to the force creating the field
- present only if the force is stationary
14. Electromagnetism is the:
- magnetic field caused by a permanent magnet
- action between a permanent and an artificial magnet
- magnetic field action with a current-carrying wire
- current in the coil
15. A magnetic field has:
- polar fields
- lines of force
- magnetomotive force
- lines of reluctance
16. Which two values are plotted on a B-H curve graph?
- reluctance and flux density
- permeability and reluctance
- magnetizing force and permeability
- flux density and magnetizing force
17. What is the number of turns required in the secondary winding for a transformer when 120 volts is applied to a 2400-turn primary to produce 7.5 Vac at the secondary?
- 75 turns
- 150 turns
- 900 turns
- 1920 turns
18. The four factors determining inductance are the number of turns, coil length, coil area, and:
- permeability
- reluctance
- counter emf
- coefficient of coupling
19. The time difference, or lag, between flux density and magnetizing force is known as:
- eddy current
- magnetic saturation
- hysteresis
- coercivity
20. A magnetic circuit breaker will open to protect equipment only when:
- voltage is exceeded
- an open is in the equipment
- the equipment is operating properly
- current is exceeded