Electronics-Inductors Question and Answer
Electronics-Inductors Question and Answer
21. Electromagnetic induction is the generation of:
- electricity from magnetism
- electricity from electricity
- magnetism from electricity
- magnetism from magnetism
22. Inductance is:
- directly proportional to the length of the coil
- directly proportional to the number of turns on the coil
- inversely proportional to the cross-sectional area of the coil
- inversely proportional to the permeability
23. Current will cause a magnetic field in a conductor as follows:
- An ac current causes a fixed polarity magnetic field.
- A dc current causes a fixed polarity magnetic field.
- A dc current causes an alternating magnetic field.
- An ac current causes a fixed polarity magnetic field and a dc current causes an alternating magnetic field.
24. During a current change, the ability of a conductor to produce counter emf within itself is called:
- back emf
- self-induction
- a henry
- impedance
25. When a transformer secondary lead has been connected to a middle loop that is not an end connector, it is called a:
- multiple-tapped secondary
- center-tapped secondary
- multiple winding secondary
- single winding secondary
26. What will happen when an inductor's magnetic field collapses?
- Current will double.
- Voltage will be induced.
- A new field will expand.
- Counter emf will be high.
27. With a square wave input, an RL differentiator circuit with an output across the inductor will produce what type of waveform?
- dc
- short time-duration pulses
- exponential-shaped pulses
- only a phase shift
28. When a magnet enters a coil and a voltage is induced, the process is known as:
- an alternation
- self-inductance
- counter emf
- flux linkage
29. What term is used to describe the action of magnetic flux from one circuit that cuts across the conductors of another circuit?
- self-inductance
- rectification
- mutual inductance
- magnetism
30. Reactance in an inductive circuit will:
- increase with frequency
- decrease with frequency
- be independent from frequency
- depend on the value of XC