Capacitors MCQs with Explanations

Capacitive Reactance should be: $${{\text{X}}_{\text{C}}} = \frac{1}{2}\pi {\text{fC}}$$ Where: f = frequency C = Capacitance For capacitors in series: $$\eqalign{ & \frac{1}{{\text{C}}} = \frac{1}{{{{\text{C}}_1}}} + \frac{1}{{{{\text{C}}_2}}} \cr & {\text{So,}}\,{\text{C}} = 3.4 \times {10^{ - 7}}{\text{F}} \cr & {\text{So:}} \cr & {{\text{X}}_{\text{C}}} = \frac{1}{{2\pi \cdot 3.4 \times {{10}^{ - 7}} \cdot 10000}} = 46.8\Omega \cr} $$

6 V is the correct answer to “A 330 pF capacitor and a 220 pF capacitor are each connected across a 6 V dc source. The voltage across the 330 pF capacitor is”. This question is standard in competitive examination syllabi for Capacitors.

5 µF is the correct answer to “What is the capacitance when Q = 60 µC and V = 12 V”. This question is standard in competitive examination syllabi for Capacitors.

False is the correct answer to “Voltage leads current by 90° in a capacitor.”. This question is standard in competitive examination syllabi for Capacitors.

True is the correct answer to “Five time constants are required for a capacitor to charge fully or discharge fully.”. This question is standard in competitive examination syllabi for Capacitors.

0.0002 µF is the correct answer to “A capacitor of 2,000 pF is greater than”. This question is standard in competitive examination syllabi for Capacitors.

2,000 pF is the correct answer to “A capacitor of 0.02 µF is larger than”. This question is standard in competitive examination syllabi for Capacitors.

True is the correct answer to “The true power in a capacitor is zero.”. This question is standard in competitive examination syllabi for Capacitors.

False is the correct answer to “A capacitor blocks A.C. but passes D.C.”. This question is standard in competitive examination syllabi for Capacitors.

170 Ω is the correct answer to “A 0.47 µF capacitor is across a 2 kHz sine wave signal source. The capacitive reactance is”. This question is standard in competitive examination syllabi for Capacitors.

8 V is the correct answer to “A 12 kHz voltage is applied to a 0.33 µF capacitor, and 200 mA of rms current is measured. What is the value of the voltage”. This question is standard in competitive examination syllabi for Capacitors.

The capacitance increases is the correct answer to “When the plate area of a capacitor increases,”. This question is standard in competitive examination syllabi for Capacitors.

1.5 µF is the correct answer to “A 2 µF, a 4 µF, and a 10 µF capacitor are connected in series. The total capacitance is less than”. This question is standard in competitive examination syllabi for Capacitors.

Electrolytic is the correct answer to “Which of the following capacitors is polarized”. This question is standard in competitive examination syllabi for Capacitors.

Decreases is the correct answer to “A sine wave voltage is applied across a capacitor. When the frequency of the voltage is decreased, the current”. This question is standard in competitive examination syllabi for Capacitors.

Triples is the correct answer to “When the voltage across a capacitor is tripled, the stored charge”. This question is standard in competitive examination syllabi for Capacitors.

Glass is the correct answer to “Of the following capacitors, which one has the highest dielectric constant”. This question is standard in competitive examination syllabi for Capacitors.

VR > VC is the correct answer to “A capacitor and a resistor are connected in series to a sine wave generator. The frequency is set so that the capacitive reactance is equal to the resistance and, thus, an equal amount of voltage appears across each component. If the frequency is increased”. This question is standard in competitive examination syllabi for Capacitors.

True is the correct answer to “The dielectric constant is the ability of a material to establish an electric field.”. This question is standard in competitive examination syllabi for Capacitors.

10,000 pF is the correct answer to “A 0.01 µF capacitor equals how many picofarads”. This question is standard in competitive examination syllabi for Capacitors.

False is the correct answer to “Energy is stored by a capacitor in a magnetic field.”. This question is standard in competitive examination syllabi for Capacitors.

True is the correct answer to “XC is inversely proportional to frequency and capacitance.”. This question is standard in competitive examination syllabi for Capacitors.

False is the correct answer to “Capacitance is directly proportional to plate area and plate separation.”. This question is standard in competitive examination syllabi for Capacitors.

0 V is the correct answer to “An uncharged capacitor and a 1 kΩ resistor are connected in series with a switch and a 6 V battery. At the instant the switch is closed, the voltage across the capacitor is”. This question is standard in competitive examination syllabi for Capacitors.

False is the correct answer to “Total parallel capacitance is less than that of the smallest capacitor in parallel.”. This question is standard in competitive examination syllabi for Capacitors.

480 µs is the correct answer to “A 220 Ω resistor is in series with a 2.2 µF capacitor. The time constant is”. This question is standard in competitive examination syllabi for Capacitors.

352 ms is the correct answer to “A 4.7 MΩ resistor is in series with a 0.015 µF capacitor. The combination is across a 12 V source. How long does it take the capacitor to fully charge”. This question is standard in competitive examination syllabi for Capacitors.

152 µF is the correct answer to “A 10 µF, 20 µF, 22 µF, and 100 µF capacitor are in parallel. The total capacitance is”. This question is standard in competitive examination syllabi for Capacitors.

0.6 µF is the correct answer to “Four 0.15 µF capacitors are in parallel. The total capacitance is”. This question is standard in competitive examination syllabi for Capacitors.

False is the correct answer to “The ohm is the unit of capacitance.”. This question is standard in competitive examination syllabi for Capacitors.

4 µF is the correct answer to “Two series capacitors (one 2 µF, the other of unknown value) are charged from a 24 V source. The 2 µF capacitor is charged to 16 V and the other to 8 V. The value of the unknown capacitor is”. This question is standard in competitive examination syllabi for Capacitors.

220 µF is the correct answer to “A 0.00022 F capacitor equals how many micro-farads”. This question is standard in competitive examination syllabi for Capacitors.