Power supplies

Question 1

Batteries in series add voltages where batteries in parallel add currents.

Answer 1

true

Question 2

A dual-voltage power supply is also called a ? .

Answer 2

bipolar supply

Question 3

Which of the following is not one of the steps or processes involved in a complete power supply system?

Answer 3

Combining the outputs of the taps

Question 4

When connecting power supplies that convert AC to DC, note that the ? will determine the load polarity.

Answer 4

diode polarity

Question 5

If the waveform across a load resistor is observed to be half-wave pulsating direct current, the rectifier is classified as a ? rectifier.

Answer 5

half-wave

Question 6

Which of the following represents a half-wave rectifier for the positive input half cycle?

Answer 6

b

Question 7

Which of the following represents the waveform across RL?

Answer 7

a

Question 8

Find the effective (rms) voltage of the “AC source.“ Hint: This is a pure sine-wave calculation; do not deduct for the diode.

Answer 8

Vp = Vp - p/2

Veff = Vp/sq root 2

Question 9

The half-wave average voltage across load RL is ? . Hint: The deduction for the diode must be included in the calculation. Calculate your answer to two decimal places.

Answer 9

Vp(load) = Vp(xfmr) - Vd

Vl(avg) = Vp(load)/pi

Question 10

The peak current through load RL is ? . Calculate your answer to three decimal places.

Answer 10

Ip(load) = Vp(xmfr) - Vd/Rl

Question 11

A ? rectifier uses a center-tapped transformer secondary and two diodes.

Answer 11

full-wave

Question 12

A waveform across the load of a full-wave rectifier is pulsating direct current with half the peak voltage of the secondary because of the center-tap.

Answer 12

true

Question 13

The AC input cycle is divided into two parts: the positive alternation and the negative alternation.

Answer 13

true

Question 14

A full-wave rectifier that does not use a center-tapped transformer and utilizes four diodes to provide full-wave rectification is called a ? rectifier.

Answer 14

bridge

Question 15

Which of the following represents a full-wave rectifier with a center-tapped transformer and a connected load?

Answer 15

a

Question 16

Which of the following represents an output waveform that results from two input cycles on a full-wave rectifier?

Answer 16

B

full wave on top

Question 17

Which of the following represents a full-wave rectifier with lines and arrows to indicate direction of electron flow for the positive half of input cycle?

Answer 17

a

Question 18

Which of the following represents a full-wave rectifier with lines and arrows to indicate direction of electron flow for the negative half of input cycle?

Answer 18

b

Question 19

The image represents a ? with load RL.

Answer 19

full-wave bridge rectifier

Question 20

The peak voltage across RL is ? . Calculate your answer to one decimal space.

Answer 20

Vrl(peak) = Vp - (Vd + Vd)

Question 21

The rectifier converts AC to a(n) pulsating DC voltage.

Answer 21

true

Question 22

The average voltage across RL is ? . Calculate your answer to two decimal places.

Answer 22

Vave = 2 x Vp/pi

Question 23

Which of the following is a method used to measure rectified voltages in a half-wave rectifier?

Answer 23

Peak average

Peak-to-peak

Rms

Question 24

Which of the following formulas is used to find the peak voltage of an un-rectified sine wave?

Answer 24

Vp = Vp-p/2

Question 25

Which of the following formulas is used to find the rms value of a half-wave rectifier?

Answer 25

Vrms = Vp-p/pi