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17 Cards in this Set
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Q1. What effect does an inductor have on a change in current?

A1. An inductor opposes a change in current.

Q2. What is the phase relationship between current and voltage in an inductor?

A2. Current lags voltage by 90º (ELI).

Q3. What is the term for the opposition an inductor presents to ac?

A3. Inductive reactance.

Q4. What is the formula used to compute the value of this opposition?

A4. XL = 2πfL.

Q5. What happens to the value of XL as frequency increases?

A5. XL increases.

Q6. What happens to the value of XL as inductance decreases?

A6. XL decreases.

Q7. What effect does the capacitor have on a changing voltage?

A7. The capacitor opposes any change in voltage.

Q8. What is the phase relationship between current and voltage in a capacitor?

A8. Current leads voltage by 90º (ICE).

Q9. What is the term for the opposition that a capacitor presents to ac?

A9. Capacitive reactance.

Q10. What is the formula used to compute this opposition?

skip

Q15. What term is given to total opposition to ac in a circuit?

A15. Impedance.

Q19. What is the true power in an ac circuit?

A19. True power is the power dissipated in the resistance of the circuit or the power actually used in
the circuit. 
Q20. What is the unit of measurement of true power?

A20. Watt.

Q21. What is the formula for calculating true power?

A21. True Power = (IR) 2R.

Q22. What is the reactive power in an ac circuit?

A22. Reactive power is the power returned to the source by the reactive components of the circuit.

Q23. What is the unit of measurement for reactive power?

A23. var.

Q31. What is the difference between calculating impedance in a series ac circuit and in a parallel ac
circuit? 
A31. In a series circuit impedance is calculated from the values of resistance and reactance. In a
parallel circuit, the values of resistive current and reactive current must be used to calculate total current (impedance current) and this value must be divided into the source voltage to calculate the impedance. 