Review questions and
answers 2024\2025
Grade A+
What constititues a capacitor?
- correct answer Two conductors separated by an insulator.
What is the purpose of a capacitor?
- correct answer Stores electrical energy in electrostatic fields.
Does a capacitor cause current to lead or lag voltage in an AC Circuit?
- correct answer Lead Voltage.
What is the basic unit of capacitance?
- correct answer Farad.
,Why shouldn't electrolytic capacitors be used in an AC circuit?
- correct answer They are polarized, it will pass current of one polarity and block the opposite.
What is meant by inductance?
- correct answer Ability to store electrical energy in electromagnetic fields.
what is the basic unit of inductance?
- correct answer Henry.
What is an example of an inductor used in a magneto?
- correct answer The Coil.
Does an inductor cause current to lead or lag voltage in an AC Circuit?
- correct answer Lag.
How can you find the polarity of an electromagnet?
- correct answer Hold the electromagnet in your left hand with your fingers encircling the coil in the
direction electrons flow. Your thumb will point to the north pole.
What is meant by impedance?
- correct answer The total opposition to the flow of alternating current. It is the vector sum of
resistance,capacitive reactance, and inductive reactance.
In what units is impedance measured?
- correct answer Ohms.
What are the five sources of electrical energy?
- correct answer Magnetism, chemical energy, light, heat, and pressure.
What is the basic unit of power in a DC circuit?
- correct answer Watt.
,What is meant by a Kilowatt?
- correct answer 1,000 watts.
What is meant by a Megawatt?
- correct answer 1,000,000 watts.
What is the formula for power in a DC circuit?
- correct answer Power=Voltage*Current (P=E*I).
What is the relationship between mechanical and electrical power?
- correct answer 1 Horsepower=746 Watts.
What is meant by true power in an AC Circuit?
- correct answer The product of circuit voltage and the current in phase with that voltage.
In what unit is true power expressed?
- correct answer Watts.
What is meant by apparent power in an AC circuit?
- correct answer The product of circuit voltage and circuit current.
In what units is apparent power expressed?
- correct answer Volt-Amps.
What is meant by reactive power in an AC circuit?
- correct answer The power consumed in the inductive and capacitive reactances in an AC circuit.
Reactive power is also called wattless power.
In what units is reactive power expressed?
- correct answer Volt-Amps reactive, or Kilovolt-amps reactive.
, What is meant by the power factor in an AC circuit?
- correct answer The ratio to true power and apparent power. Also the ratio of circuit resistance and
circuit impedance.
Which law of electricity is the most important?
- correct answer Ohm's Law.
What are the elements of Ohm's Law?
- correct answer Voltage E, current I, and resistance R.
What is voltage?
- correct answer Electrical pressure.
What is the basic unit of voltage?
- correct answer Volt.
What instrument is used to measure voltage?
- correct answer Voltmeter.
Is a voltmeter placed in series or parallel to measure voltage?
- correct answer Parallel.
What is electrical current?
- correct answer The flow of electrons in a circuit.
What is the basic unit of current flow?
- correct answer Amp or ampere.
What part of an amp is a milliamp?
- correct answer One thousandth of an amp. (0.001)
What instrument is used to measure current?
- correct answer Ammeter.