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| 1 | In a capacitive circuit, the current delivered to a capacitor will rise to 63 percent of its maximum value after charging for a period of one time constant. |
 | A) | True |
| B) | False |
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| 2 | In an inductive circuit, the current decays to 37 percent of its initial value in a period of one time constant. |
| A) | True |
| B) | False |
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| 3 | A capacitor with a breakdown voltage of 150 V would be safe to use in an ac circuit if the ac voltage were only 120 V |
| A) | True |
| B) | False |
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| 4 | Capacitive reactance and inductive reactance increase with an increase in frequency of an alternating current. |
| A) | True |
| B) | False |
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| 5 | The effective voltage V in a series ac circuit can be defined as the algebraic sum of VC, VL, and VR. |
| A) | True |
| B) | False |
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| 6 | The power factor in an ac circuit is the ratio of its resistance to its impedance. |
| A) | True |
| B) | False |
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| 7 | Under a condition of resonance in an ac circuit, the current will be in phase with the voltage. |
| A) | True |
| B) | False |
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| 8 | Reactance, impedance, and resistance are all measured in the same physical unit (ohms). |
| A) | True |
| B) | False |
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| 9 | In a circuit containing pure capacitance, the voltage leads the current by 90°. |
| A) | True |
| B) | False |
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| 10 | A negative phase angle occurs when the current leads the voltage in an ac circuit. |
| A) | True |
| B) | False |
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| 11 | The voltage of a circuit containing only inductive reactance |
| A) | is in phase with the current |
| B) | leads the current by 90° |
| C) | lags the current by 90° |
| D) | leads the current by less than 90° |
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| 12 | An alternating voltage has a maximum value of 30 V. The effective value is approximately |
| A) | 15 V |
| B) | 21.2 V |
| C) | 30 V |
| D) | 42.9 V |
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| 13 | As the capacitance in an ac circuit increases, the resonant frequency |
| A) | increases |
| B) | decreases |
| C) | remains the same |
| D) | approaches zero |
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| 14 | The ratio of the pure resistance in an ac circuit to the impedance is known as the |
| A) | power factor |
| B) | phase angle |
| C) | resonant frequency |
| D) | net reactance |
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| 15 | In a circuit containing pure capacitance, during a period of one time constant, the |
| A) | charge decays to 63 percent of its initial value |
| B) | charge increases to 37 percent of its initial value |
| C) | current decays to 37 percent of its initial value |
| D) | capacitor is completely charged |
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| 16 | In an ac circuit containing a coil with an inductance of 0.3 H, the voltage is 120 V at 60 Hz. If we neglect resistance, the effective current in the coil is |
| A) | 0.27 A |
| B) | 0.53 A |
| C) | 1.06 A |
| D) | 2.12 A |
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| 17 | A 50-Ω resistor, a 0.5-H inductor, and a 12- μF capacitor are connected in series with a 120-V, 60-Hz alternating current. The effective current is approximately |
| A) | 2 A |
| B) | 4 A |
| C) | 6 A |
| D) | 8 A |
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| 18 | In Question 17, the power factor is |
| A) | 0.66 |
| B) | 0.72 |
| C) | 0.83 |
| D) | 0.92 |
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| 19 | An 800-Ω resistor, a 0.6-H inductor, and a 4- μF capacitor are connected in series with a 220-V, 50-Hz source of alternating current. The phase angle is approximately |
| A) | -31° |
| B) | -37° |
| C) | 31° |
| D) | 37° |
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| 20 | A circuit contains a 12-μF capacitor, a 40-Ω resistor, a switch, and a 20-V dc battery connected in series. After the switch is closed, the capacitor can be considered
fully charged after |
| A) | 0.00048 s |
| B) | 0.0012 s |
| C) | 0.0024 s |
| D) | 0.0048 s |
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| 21 | One effective ampere is that alternating current that will develop the same as of direct current. |
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| 22 | In a(n) circuit, the current decays to 37 percent of its initial value in a period equal to one . |
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| 23 | In a capacitive circuit, the leads the , and the phase angle is . |
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| 24 | For an ac circuit containing capacitance, inductance, and resistance, the current will be a maximum when the frequency of the alternating voltage is equal to . |
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| 25 | The power factor is equal to the of the circuit divided by the . |
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| 26 | When the voltage and current reach maximum and minimum values at the same time, they are said to be . |
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| 27 | A given inductor has an inductance of one if an emf of one is induced by a current changing at the rate of one . |
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| 28 | In an inductive circuit, an increase in frequency of the applied voltage will the effective current. |
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| 29 | At resonant frequency, an ac circuit containing resistance, inductance, and capacitance acts as if it contained only . |
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| 30 | A household ac circuit has a 110-V, 60-Hz source of current. The actual voltage varies from to . |