Chapter 8: Alternating Current

In North America, the frequency of AC utility voltage is 60Hz. The period is

• 8.3ms

• 16.7ms

• 60ms

• 60s

The amplitude of a sine wave is measured

• at the maximum point

• between the minimum and maximum points

• at the midpoint

• anywhere on the wave

An example of an equation for a waveform that lags the reference is

• v = -40V sin (theta)

• v = 100V sin (theta + 35deg)

• v = 5V sin (theta - 27deg)

• v = 27V

In the equation v = Vp Sin (theta), the letter v stands for the

• peak value

• average value

• rms value

• instantaneous value

A sawtooth waveform has

• equal positive and negative going ramps

• two ramps - one much longer than the other

• two equal pulses

• two unequal pulses

The number of radians in 90 degree are

• pi / 2

• pi

• 2pi / 3

• 2pi

For the waveform shown, the same power would be delivered to a load with a DC voltage of

• 21.2V

• 37.8V

• 42.4V

• 60.0V