Discussion
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- Question
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
Options- A. 3 V
- B. 6 V
- C. 4 V
- D. 0 V
- Correct Answer
- 6 V
- 1. A capacitor of 0.02 µF is larger than
Options- A. 0.000020 F
- B. 200,000 pF
- C. 2,000 pF
- D. all of the above Discuss
- 2. A 0.47 µF capacitor is across a 2 kHz sine wave signal source. The capacitive reactance is
Options- A. 170 Ω
- B. 17 Ω
- C. 0.000169 Ω
- D. 1.7 Ω Discuss
- 3. In Question 6, the capacitor will reach full charge in a time equal to approximately
Options- A. 6 RC
- B. 5 RC
- C. RC
- D. none of the above Discuss
- 4. 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
Options- A. VR > VC
- B. VC > VR
- C. VR = VC
- D. VR and VC = 0 Discuss
- 5. When the voltage across a capacitor is tripled, the stored charge
Options- A. triples
- B. is cut to one-third
- C. stays the same
- D. doubles Discuss
- 6. A capacitor of 2,000 pF is greater than
Options- A. 0.02 µF
- B. 0.002 µF
- C. 0.0002 µF
- D. 0.0000002 F Discuss
- 7. In a certain loaded transformer, the secondary voltage is one-fourth the primary voltage. The secondary current is
Options- A. one-fourth the primary current
- B. four times the primary current
- C. equal to the primary current
- D. one-fourth the primary current and equal to the primary current Discuss
- 8. To step 110 V ac down to 20 V ac, the turns ratio must be
Options- A. 5.5
- B. 18
- C. 0.18
- D. 0.018 Discuss
- 9. When a 200 Ω load resistor is connected across the secondary winding of a transformer with a turns ratio of 4, the source "sees" a reflective load of
Options- A. 50 Ω
- B. 12.5 Ω
- C. 800 Ω
- D. 0 Ω Discuss
- 10. What kVA rating is required for a transformer that must handle a maximum load current of 8 A with a secondary voltage of 2 kV?
Options- A. 4 kVA
- B. 0.25 kVA
- C. 16 kVA
- D. 8 kVA Discuss
Capacitors problems
Search Results
Correct Answer: 2,000 pF
Correct Answer: 170 Ω
Correct Answer: 5 RC
Correct Answer: VR > VC
Correct Answer: triples
Correct Answer: 0.0002 µF
Correct Answer: four times the primary current
Correct Answer: 0.18
Explanation:
Vp/Vs = Np/Ns
Vs = (Ns/Np)Vp
We required turns ratio i.e., (Ns/Np)
= Vs/Vp
= 20/110
= 0.181818182
[Note: p - primary; s - secondary]
For step down transfer, the turns ratio will be less than 1.
For simulation: Step-Down Transformer Circuit Simulator.
Vs = (Ns/Np)Vp
We required turns ratio i.e., (Ns/Np)
= Vs/Vp
= 20/110
= 0.181818182
[Note: p - primary; s - secondary]
For step down transfer, the turns ratio will be less than 1.
For simulation: Step-Down Transformer Circuit Simulator.
Correct Answer: 12.5 Ω
Correct Answer: 16 kVA
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