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This section includes 10 Mcqs, each offering curated multiple-choice questions to sharpen your Physics knowledge and support exam preparation. Choose a topic below to get started.
1. |
Which among the following is the correct expression for finding capacitive reactance for an ac circuit containing capacitor only? |
A. | Xc = 2πf |
B. | Xc = \(\frac {1}{2πfC}\) |
C. | Xc = 2πfC |
D. | Xc = \(\frac {2πf}{C}\) |
Answer» C. Xc = 2πfC | |
2. |
A 1.50 μF capacitor is connected to a 220 V, 50 Hz source. If the frequency is doubled, what happens to the capacitive reactance? |
A. | Remains the same |
B. | Doubled |
C. | Halved |
D. | Becomes zero |
Answer» D. Becomes zero | |
3. |
What will be the reactance of a capacitor at 150 Hz, if it has a reactance of 200 Ω at 50 Hz? |
A. | 67 Ω |
B. | 40 Ω |
C. | 150 Ω |
D. | 60 Ω |
Answer» B. 40 Ω | |
4. |
Calculate the rms value of current in the circuit wherein an 80 μF capacitor is connected to a 100 V, 80 Hz ac supply. |
A. | 4 A |
B. | 2 A |
C. | 7 A |
D. | 50 A |
Answer» B. 2 A | |
5. |
The capacitive reactance varies directly with the frequency. |
A. | True |
B. | False |
Answer» C. | |
6. |
Give the SI unit of capacitive reactance. |
A. | Am |
B. | Ω |
C. | Ωm |
D. | A |
Answer» D. A | |
7. |
How will the capacitive reactance be affected if the frequency is doubled? |
A. | Doubled |
B. | Insignificant |
C. | Remains the same |
D. | Halved |
Answer» E. | |
8. |
What is the capacitive reactance of a 5 μF capacitor when it is a part of a circuit whose frequency is 50 Hz? |
A. | 636.6 Ω |
B. | 1636.6 Ω |
C. | 2636.6 Ω |
D. | 4636.6 Ω |
Answer» B. 1636.6 Ω | |
9. |
A capacitor of capacitance 10 μF is connected to an oscillator giving an output voltage, E = 10 sin ωt volt. If ω = 10 rad s-1, find the peak current in the circuit. |
A. | 197 mA |
B. | 1 mA |
C. | 179 mA |
D. | 5 mA |
Answer» C. 179 mA | |
10. |
A 1.5 μF capacitor is connected to a 220 V, 50 Hz source. Find the capacitive reactance in the circuit. |
A. | 2120 Ω |
B. | 21.2 Ω |
C. | 212 Ω |
D. | 2.12 Ω |
Answer» D. 2.12 Ω | |