E5B Time constants and phase relationships: RL and RC time constants; phase angle in reactive circuits and components; admittance and susceptance
- E5B01 (B)
What is the term for the time required for the capacitor in an RC circuit to be charged to 63.2% of the applied voltage or to discharge to 36.8% of its initial voltage? #card
- A. An exponential rate of one
- B. One time constant
- C. One exponential period
- D. A time factor of one
- E5B02 (D)
What letter is commonly used to represent susceptance? #card
- E5B03 (B)
How is impedance in polar form converted to an equivalent admittance? #card
- A. Take the reciprocal of the angle and change the sign of the magnitude
- B. Take the reciprocal of the magnitude and change the sign of the angle
- C. Take the square root of the magnitude and add 180 degrees to the angle
- D. Square the magnitude and subtract 90 degrees from the angle
- E5B04 (D)
What is the time constant of a circuit having two 220-microfarad capacitors and two 1-megohm resistors, all in parallel? #card
- A. 55 seconds
- B. 110 seconds
- C. 440 seconds
- D. 220 seconds
- E5B05 (D)
What is the effect on the magnitude of pure reactance when it is converted to susceptance? #card
- A. It is unchanged
- B. The sign is reversed
- C. It is shifted by 90 degrees
- D. It is replaced by its reciprocal
- E5B06 (C)
What is susceptance? #card
- A. The magnetic impedance of a circuit
- B. The ratio of magnetic field to electric field
- C. The imaginary part of admittance
- D. A measure of the efficiency of a transformer
- E5B07 (C)
What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 500 ohms, R is 1 kilohm, and XL is 250 ohms? #card
- A. 68.2 degrees with the voltage leading the current
- B. 14.0 degrees with the voltage leading the current
- C. 14.0 degrees with the voltage lagging the current
- D. 68.2 degrees with the voltage lagging the current
- E5B08 (A)
What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 300 ohms, R is 100 ohms, and XL is 100 ohms? #card
- A. 63 degrees with the voltage lagging the current
- B. 63 degrees with the voltage leading the current
- C. 27 degrees with the voltage leading the current
- D. 27 degrees with the voltage lagging the current
- E5B09 (D)
What is the relationship between the AC current through a capacitor and the voltage across a capacitor? #card
- A. Voltage and current are in phase
- B. Voltage and current are 180 degrees out of phase
- C. Voltage leads current by 90 degrees
- D. Current leads voltage by 90 degrees
- E5B10 (A)
What is the relationship between the AC current through an inductor and the voltage across an inductor? #card
- A. Voltage leads current by 90 degrees
- B. Current leads voltage by 90 degrees
- C. Voltage and current are 180 degrees out of phase
- D. Voltage and current are in phase
- E5B11 (B)
What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 25 ohms, R is 100 ohms, and XL is 75 ohms? #card
- A. 27 degrees with the voltage lagging the current
- B. 27 degrees with the voltage leading the current
- C. 63 degrees with the voltage lagging the current
- D. 63 degrees with the voltage leading the current
- E5B12 (A)
What is admittance? #card
- A. The inverse of impedance
- B. The term for the gain of a field effect transistor
- C. The inverse of reactance
- D. The term for the on-impedance of a field effect transistor
