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