Electronics-Inductors Question and Answer
Electronics-Inductors Question and Answer
31. A turns ratio of 5 for a transformer implies:
- more primary turns than secondary turns
- more secondary current than primary current
- larger source impedance than load impedance
- more secondary turns than primary turns
32. A practical inductor
- has inductance
- has winding resistance
- has winding capacitance
- all of the above
33. When current in an inductor starts to change, it cannot react instantly due to:
- fixed coil resistance
- eddy current generation
- applied emf of the circuit
- the counter emf of the coil
34. What is the approximate time for a complete decay of 400 mA of inductor current, when R = 10 ohms and L = 20 H?
- 10 seconds
- 8 seconds
- 4 seconds
- 2 seconds
35. A utility pole transformer used to supply a residential customer with two phases uses:
- two phases on the primary
- a center tap on the secondary
- a separate ground for each phase
- a small coefficient of coupling
36. When a coil collapses the induced circuit current will:
- be in the same direction
- go to zero
- aid counter emf buildup
- be in the opposite direction
37. When a rate of one ampere per second causes an induced voltage of one volt, the unit of measure is
- a lenz
- an ohm
- a farad
- a henry
38. If you wanted to decrease the inductance of a coil, you might increase the:
- number of turns
- permeability of the core
- spacing between turns
- area of the coil
39. The output phase for a transformer is:
- in phase with the input
- out of phase with the input
- dependent on the direction of the primary and secondary windings
- dependent on the frequency of the primary source
40. Opposition to current flow without the dissipation of energy is called:
- resistance
- inductive reactance
- counter emf
- impedance