1. The most common source of alternating voltage is ?

- AC generator
**correct** - Motor
- Transformer
- Both A & B
- Both A & C

2. The alternating voltage or current is actually measured by ?

- Its RMS value
- Square root of its mean square value
- Peak value
- Instantaneous value
- Both A & B
**correct**

3. The highest value reached by the voltage or current ?

- In quarter cycle is called instantaneous value
- None of these
- In one cycle is called peak value
**correct** - In half cycle is called peak-to-peak value
- In half cycle is called instantaneous value

4. The phase at the negative peak of an A. C. cycle is ?

- 90º
- 270º
**correct** - 180º
- 0º
- 360º

5. Peak value of alternating current is ?

- Equal to its RMS value
- One of its instantaneous values
**correct** - None of these
- The same as its peak-to-peak value
- Both B and C

6. The entire waveform of sinusoidal voltage is actually a set of all the ?

- Instantaneous values which exist during a period T
**correct** - RMS values
- Peak-to-peak values
- None of tehse
- Average values which exist during a period T/2

7. A sinusoidally alternating voltage or current can be graphically represented by a ?

- None of these
- Clockwise rotating vector
- Anti clock wise voltage vector
**correct** - Vector
- Rotating vector

8. Nowadays, most of the electrical energy is produced by A.C. generators using ?

- Solar energy
- Both B & D
- Hydal water
**correct** - Biomass
- Geothrmal energy

9. Unless stated otherwise, when we speak of A.C. meter reading, we usually mean ?

- Instantaneous value
- Peak-to-peak value
- RMS value
**correct** - Both A & C
- Peak value

10. The RMS value of alternating voltage is ?

- 0.7 times the peak value
**correct** - 0.5 times the peak value
- None of these
- 0.7 times the instantaneous value
- Equal to maximum voltage

11. The waveform of alternating voltage is a ?

- Sinusoidal
**correct** - Rectangular
- None of these
- Saw-tooth
- Square

12. The time interval during which source changes its polarity once is knows as ?

- Quarter the time period
- Half the time period
- None of these
- Two third of the time period
- Time period T
**correct**

13. If we connect an A.C. voltmeter to read A.C. voltage, it would read its ?

- Both B and C
- RMS value
**correct** - Instantaneous value
- Value averaged over a cycle
- Zero

14. If 250V is the RMS value of alternating voltage, then its peak value V, will be ?

- 400 V
- 175 V
- Zero
- 250 V
- 353.5 V
**correct**

15. The length of the rotating vector (on a certain scale) represents the ?

- Instantaneous value of alternating quantity
- RMS value of a alternating quantity
- Either A or B
**correct** - Peak value of alternating quantity
- Either B or C

16. Alternating current is produced by a voltage source which polarity ?

- Remains the same
- Keeps on reversing with time
- Reverses after period T
- Both C & D
**correct** - Reverses after every time interval T/2

17. Alternating current can be transmitted ?

- To long distance at very low cost
**correct** - To long distance at very high cost
- At very low cost
- To long distance

18. The magnitude of alternating voltage V ?

- Always increases
- None of these
- Remains constant
- Always decreases
- Des not remain constant
**correct**

19. If we connect an ordinary DC ammeter to measure alternating current, it would measure its ?

- Value averaged over a cycle
**correct** - RMS value
- Instantaneous value
- Either B or C

20. The sum of positive and negative peak value) i,e., p-p value) is called ?

- None of these
- Instantaneous value
- RMS value
- Peak-to-peak value
**correct** - Peak value

21. The wave form of alternating voltage is the graph between ?

- Either B or D
- Voltage along y-axis and time along x-axis
**correct** - Voltage along x-axis and along y-axis
- Current and time
- Voltage and current

22. The phase at the positive peak of an A.C cycle is ?

- 0º
- 90º
**correct** - 360
- 270º
- 180º

23. The peak-to-peak value of alternating voltage is ?**A = 2V _{º}**

**B = V**

_{ º}**C = V**

_{º }/2**D = 4V**

_{ º}**E = None of these**

- D
- B
- C
- A
**correct**

24. The instantaneous value of alternating current may be ?

- The same as its peak value
**correct** - The same as its RMS value
- Greater than its RMS value
- None of tehse
- Any of these

25. The points where the waveform of an A.C. cycle cross the time axis corresponds to phase ?

- 0º
- π/2 and 3π/2
- 90º
- 180º
- 0 and π
**correct**