Gibilisco - Phase - Quiz & Trivia

1. A phase difference of 180° in the circular motion model of a sine wave represents

1⁄4 revolution.

1⁄2 revolution.

A full revolution.

Two full revolutions.

2. If wave X lags wave Y by 1⁄3 cycle, then

Wave Y is 120° ahead of wave X.

Wave Y is 90° ahead of wave X.

Wave Y is 60° ahead of wave X.

Wave Y is 30° ahead of wave X.

3. Shifting the phase of an ac sine wave by 90° is the same thing as

Moving it to the right or left by a full cycle.

Moving it to the right or left by 1⁄4 cycle.

Turning it upside down.

Leaving it alone.

4. Suppose a wave has a frequency of 300 kHz. How long does one complete cycle take?

1.300 s

0.00333 s

1/3000 s

3.33 × 10−6 s

5. The derivative of a sine wave

Is shifted in phase by 1⁄2 cycle from the sine wave.

Is the rate of change in the instantaneous value.

Has instantaneous rise and decay times.

Rises instantly, but decays slowly.

6. You can add or subtract a certain number of degrees of phase to or from a sine wave, and end
up with an inverted (upside-down) representation of the original. This number is

90, or any odd whole-number multiple of it.

180, or any odd whole-number multiple of it.

270, or any odd whole-number multiple of it.

360, or any odd whole-number multiple of it.

7. Which of the following is not a general characteristic of an ac wave?

The wave shape is identical for each cycle.

The polarity reverses periodically.

The electrons always flow in the same direction.

There is a definite frequency.

8. All sine waves

Have similar general appearance.

Have instantaneous rise and fall times.

Are in the same phase as cosine waves.

Rise instantly, but decay slowly.

9. Suppose two waves are in phase coincidence. One has peak values of 3 V and the other has
peak values of 5 V. The resultant has voltages of

+OR- 8 V pk, in phase with the composites.

+OR- 2 V pk, in phase with the composites.

+OR- 8 V pk, in phase opposition with respect to the composites.

+OR- 2 V pk, in phase opposition with respect to the composites.

10. Two pure sine waves that differ in phase by 180° can be considered to

Be offset by two full cycles.

Be in phase opposition.

Be separated by less than 1⁄4 cycle.

Have a frequency of 1⁄2 cycle.

11. You can add or subtract a certain number of degrees of phase to or from a wave, and end up
with exactly the same wave again. This number is

90, or any whole-number multiple of it.

180, or any whole-number multiple of it.

270, or any whole-number multiple of it.

360, or any whole-number multiple of it.

12. If a wave has a frequency of 440 Hz, how long does it take for 10° of a cycle to occur?

0.00273 s

0.000273 s

0.0000631 s

0.00000631 s

13. If wave X leads wave Y by 45°, then

Wave Y is 1⁄4 cycle ahead of wave X.

Wave Y is 1⁄4 cycle behind wave X.

Wave Y is 1⁄8 cycle behind wave X.

Wave Y is 1.16 cycle ahead of wave X.

14. Suppose two sine waves are in phase opposition. Wave X has a peak amplitude of 4 V and
wave Y has a peak amplitude of 8 V. The resultant has voltages of

+OR- 4 V pk, in phase with the composites.

+OR- 4 V pk, out of phase with the composites.

+OR- 4 V pk, in phase with wave X.

+OR- 4 V pk, in phase with wave Y.

Gibilisco - Phase