Key Topic 7: Waveforms

Question 1

3-7A1: What is a sine wave?

A. A constant-voltage, varying-current wave.

B. A wave whose amplitude at any given instant can be represented by the projection of a point on a wheel rotating at a uniform speed.

C. A wave following the laws of the trigonometric tangent function.

D. A wave whose polarity changes in a random manner.

Answer 1

B. A wave whose amplitude at any given instant can be represented by the projection of a point on a wheel rotating at a uniform speed.

Question 2

3-7A2: How many degrees are there in one complete sine wave cycle?

A. 90 degrees.
B. 270 degrees.
C. 180 degrees.
D. 360 degrees.

Answer 2

D. 360 degrees.

Question 3

3-7A3: What type of wave is made up of sine waves of the fundamental frequency and all the odd harmonics?

A. Square.
B. Sine.
C. Cosine.
D. Tangent.

Answer 3

A. Square.

Question 4

3-7A4: What is the description of a square wave?

A. A wave with only 300 degrees in one cycle.
B. A wave whose periodic function is always negative.
C. A wave whose periodic function is always positive.
D. A wave that abruptly changes back and forth between two voltage levels and stays at these levels for equal amounts of time.

Answer 4

D. A wave that abruptly changes back and forth between two voltage levels and stays at these levels for equal amounts of time.

Question 5

3-7A5: What type of wave is made up of sine waves at the fundamental frequency and all the harmonics?

A. Sawtooth wave.
B. Square wave.
C. Sine wave.
D. Cosine wave.

Answer 5

A. Sawtooth wave.

Question 6

3-7A6: What type of wave is characterized by a rise time significantly faster than the fall time (or vice versa)?

A. Cosine wave.
B. Square wave.
C. Sawtooth wave.
D. Sine wave.

Answer 6

C. Sawtooth wave.