Capacitor Questions and Answers
A capacitor is a key component in electronics and is frequently featured in aptitude questions and answers for exams like GATE, SSC JE, and PSU technical tests. It stores electrical energy in an electric field and plays a vital role in filtering, timing, and energy storage circuits. Understanding capacitor behavior—like charging, discharging, and reactance—is crucial for solving numerical and conceptual questions. This article provides aptitude questions with explanations that simplify the theory and application of capacitors, helping engineering students and aspirants build a strong conceptual foundation for their placement or competitive exams.
Capacitor
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48 questions
21. What is the voltage across a capacitor after being charged from a 100 V source for a period of one time constant?
- 37.8 V
- 38 V
- 63 V
- 101 V
22. Power stored from the source and then returned to the source is called:
- apparent power
- impedance power
- reactive power
- true power
23. Capacitor value markings are usually:
- alphanumeric
- color dabs
- standard
- white print
24. A source voltage across a capacitor will:
- lead the current by 90 degrees
- lead the current by 180 degrees
- lag the current by 90 degrees
- lag the current by 180 degrees
25. An 8 V power source is charging a capacitor. How many volts will be across the capacitor at the second time constant?
- 1 volt
- 3 volts
- 5 volts
- 7 volts
26. The material used between the plates of a capacitor is called its:
- insulation material
- dielectric material
- separation material
- plate-divider material
27. When a circuit consists of a capacitor and a resistor in series with a voltage source, and the voltage across the resistor is zero, then the capacitor is:
- charging
- discharging
- fully charged
- fully discharged
29. In an ac circuit, a capacitor and an output resistor are connected in series with an ac signal. What filter action will be the result?
- bandpass
- low-pass
- high-pass
- band-stop
30. A practical capacitor
- is a short to dc
- looks like a capacitor in parallel with a resistor
- is an open to ac
- stores energy in a magnetic field