Electronics-Inductors Question and Answer
Electronics-Inductors Question and Answer
61. What happens when moving expanding lines of force encounter a conductor?
- Current increases.
- Voltage is induced.
- Resistance is reduced.
- Power is increased.
62. Fixed transformers have:
- a center-tapped secondary
- multiple windings
- turns ratios that cannot be changed
- a multiple-tapped secondary
63. Which of the following represents a true equivalent of an inductor?
- An inductance in series with a resistance and a capacitance
- A capacitance in parallel with the series combination of a resistance and an inductance
- An inductance in parallel with the series combination of a resistance and a capacitance
- The only quality a real inductor has is inductance.
64. The time required for one weber of flux to cut a conductor and produce one volt is:
- one revolution
- one second
- one millisecond
- four revolutions
65. A voltage is induced in a transformer secondary winding by the action of the:
- secondary magnetic field
- primary turns ratio
- primary magnetic field
- secondary counter emf
66. What is electromagnetism?
- the magnetic field generated around a conductor when a current passes through it
- the magnetic field generated in a conductor by an external voltage
- the voltage caused by a magnetic field in a conductor
- the current generated by an external magnetic field
67. Counter emf or induced voltage is:
- inversely proportional to the change in current
- directly proportional to the change in time
- directly proportional to the inductance in henrys
- inversely proportional to the inductance in henrys
68. What are the properties that determine the inductance of a coil?
- Length of wire, number of turns, type of core material, length of core
- Number of turns, type of wire, length of core, and cross-sectional area of core
- Type of core material, number of turns, cross-sectional area of core, and length of core
- Type of core material, type of wire, number of turns, and cross-sectional area of core
69. An inductor is in series with a voltage source, an open switch, and a resistor. The instant the switch is closed, the inductor acts like
- a short
- an open
- a resistor
- a voltage source
70. What is the phase angle between the source voltage and current, when a 100 mH inductor with a reactance of 6 komega.gif, and a 1 komega.gif resistor are in series with a source?
- 0.1 degrees
- 9.0 degrees
- 61.0 degrees
- 81.0 degrees