| 1 |
In an LRC circiut, the capacitance is made one-fourth, when an resonance . Then what should be change in inductance, so that the circuit remain in resonance? |
- A. 4 times
- B. 1/4 times
- C. 8 times
- D. 2 times
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| 2 |
The AC system is preferred to DC system because: |
- A. AC voltage can be easily changed in magnitude
- B. DC motor angular velocity is affected badly
- C. High voltage AC transmission is less efficient
- D. Domestic appliance require AC voltage for their operation
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| 3 |
In Pakistan the frequency of A.C. supply is. |
- A. 50 Hz
- B. 60 Hz
- C. 45 Hz
- D. 70 Hz
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| 4 |
The unit of impedance is |
- A. Farad
- B. Henry
- C. Tesla
- D. Ohm
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| 5 |
An alternating quantity (voltage or current) is completely known if we know its: |
- A. Maximum
- B. Frequency and phase
- C. Effective value
- D. Both (a) & (b)
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| 6 |
X<sub>1</sub>is low for low frequency Fy but Xc is. |
- A. Zero
- B. Low
- C. High
- D. Same is H
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| 7 |
Vrms = |
- A. 0.7V<sub>∘</sub>
- B. <div>0.07V<sub>∘</sub></div>
- C. 0.007V<sub>∘</sub>
- D. 0.75V<sub>∘</sub>
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| 8 |
At high frequency, the current through a capacitor is |
- A. Small
- B. Infinity
- C. Zero
- D. Large
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| 9 |
The expression P = VI hold only when current and voltage are. |
- A. In phase
- B. Out of phase
- C. At right angle to each other
- D. At angle of 120 <sup>o</sup>
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| 10 |
An electromagnetic wave goes from air to glass which of the following does not change? |
- A. Radio waves
- B. X-rays
- C. Ultra violet radiation
- D. Ultra sond waves
|