Title: L/C Worksheet
Course: Electrical Theory (IC 101-IC 101) > Section: Assessments

Q: A capacitor opposes __________ changes.
- resistance
- voltage
- current
A: resistance

Q: A sinusoidal voltage is applied across an inductor. When the frequency of the voltage is increased, the current
- decreases
- increases
- does not change
- momentarily goes to zero
A: decreases

Q: At what frequency is the reactance of a 0.1μf capacitor equal to 2KΩ?
- 796 Hz
- 796K Hz
- 79.6 Hz
- 796M Hz
A: 796 Hz

Q: At what frequency is the reactance of a 50μ H inductor equal to 800Ω.
- 2.55K Hz
- 255K Hz
- 2.55M Hz
- 255M Hz
A: 2.55K Hz

Q: Calculate XC for f = 5K Hz and C = 47pf.
- 6.77M Ohms
- 677K Ohms
- 677M Ohms
- 6.77K Ohms
A: 6.77M Ohms

Q: Calculate XL for f = 5K Hz and L = 100m H.
- 314 Hz
- 3.14K Hz
- 314K Hz
- 3.14M Hz
A: 314 Hz

Q: For a 100μ H inductor and a 200μ H inductor, calculate the total inductance (no mutual inductance).
- 66 micro H
- 100 micro H
- 200 micro H
- 300 micro H
A: 66 micro H

Q: In a capacitive circuit, the current _____________ the voltage by _____________ degreees.
- leads; 90
- leads; 45
- lags; 90
- lags; 45
A: leads; 90

Q: In a DC circuit containing a capacitor, electrons will flow momentarily during.
- Charging
- Discharging
- Constant voltage
- both a and b
A: Charging

Q: In an AC circuit, electrons flow through the capacitor.
- True
- False
A: False

Q: In an AC inductive circuit, the current lags the voltage in the inductor.
- True
- False
A: True

Q: In an inductive circuit when the switch is suddenly opened,
- the magnetic field around the coil begins to collapse.
- current tries to continue to flow due to induced voltage.
- current decays rather than abruptly going to zero
A: the magnetic field around the coil begins to collapse.

Q: The capacitance value is increased by
- decreasing plate area
- increasing plate seperation
- decreasing plate seperation
- increasing plate area
- answers a and b
- answers c and d
A: decreasing plate area

Q: The following capacitors are in parallel: 10pf, 56pf, 33pf, and 68pf. What is the capacitance total?
- 6.14pf
- 10fd
- something less than 10pf
- 167pf
- 99pf
- 111pf
A: 6.14pf

Q: The induced voltage is called CEMF (counter electromotive force).
- True
- False
A: True

Q: The inducted voltage caused by inductance opposes any change in circuit current.
- True
- False
A: True

Q: When the current through an inductor increases, the amount of energy stored in the electromagnetic field
- decreases
- remains constant
- increases
- doubles
A: decreases

Q: Which of the following accurately describes a capacitor?
- The plates are conductive.
- The dielectric is an insulator between the plates.
- There is constant direct current (DC) through a fully charged capacitor.
- A capacitor stores charge indefinitely when disconnected from the source.
- answers a and b
A: The plates are conductive.

Q: Which of the following will increase an inductors inductance value?
- Decrease core permeability.
- Lengthen the coil.
- Add turns to the coil.
A: Decrease core permeability.

Q: Which one of the following statements is true?
- There is current through the dielectric of a charging capacitor.
- When a capacitor is connected to a DC voltage source, it will charge to the value of the source.
- A capacitor can be discharged by disconnecting it from the voltage source.
A: There is current through the dielectric of a charging capacitor.