Question 1

. For the transformer shown, which current and voltage have the greatest values?
A) IP and VP
B) IS and VS
C) IP and VS
D) IS and VP

Accepted Answer

C

Question 2

A positive full-wave rectifier has a secondary voltage of 20 Vpk. The peak load voltage for the circuit is
A) 20 Vpk.
B) 9.3 Vpk.
C) 19.3 Vpk.
D) 10 Vpk.

Accepted Answer

B

Question 3

A rectifier is used to
A) convert ac to pulsating dc.
B) reduce the variations in a pulsating dc signal.
C) maintain a constant power supply dc output voltage.
D) convert one dc level to another.

Accepted Answer

A rectifier is primarily used to convert alternating current (ac) to pulsating direct current (dc).

Question 4

The term leaky is used to describe a capacitor that is
A) partially open.
B) partially shorted.
C) too high in value.
D) too low in value.

Accepted Answer

A leaky capacitor is one that has lost its ability to fully block DC current, behaving as if it has a partial short circuit. This condition allows some DC current to pass through it, which is not the intended function of a capacitor in most circuits.

Question 5

The term full load means
A) load resistance has increased to its maximum value.
B) load resistance has decreased to its minimum value.
C) the load is disconnected from the circuit.
D) load current has decreased to its minimum value.

Accepted Answer

Full load refers to the condition where the load resistance is at its minimum value, resulting in maximum current flow through the circuit.

Question 6

-When testing a basic power supply, you see that the primary fuse is blown. This typically indicates that
A) a short exists somewhere in the power supply.
B) an open exists somewhere in the power supply.
C) the fuse itself is the most likely cause of the circuit failure.
D) Any of the above conditions could exist.

Accepted Answer

A blown fuse often indicates a short circuit somewhere in the power supply, as the excessive current flow would cause the fuse to blow in order to protect the circuit.

Question 7

A filtered half-wave rectifier has a peak secondary voltage of 20 Vpk. The PIV rating for any diode in the circuit must be at least
A) 20 V.
B) 30 V.
C) 10 V.
D) 40 V.

Accepted Answer

The PIV (Peak Inverse Voltage) rating for a diode in a half-wave rectifier must be at least equal to the peak secondary voltage, but to ensure reliability and account for potential spikes, it is recommended to have a PIV rating significantly higher than the peak voltage. In this case, a PIV of 40 V provides a safe margin above the 20 Vpk.

Question 8

A half-wave rectifier is connected to a transformer with a secondary voltage of 20 Vpk. The average output voltage is
A) 19.3 Vdc.
B) 13.7 Vdc.
C) 6.14 Vdc.
D) 12.3 Vdc.

Accepted Answer

The average output voltage of a half-wave rectifier is Vavg = Vpk/π. Given Vpk = 20 V, Vavg = 20/π ≈ 6.37 Vdc. However, considering diode drop (typically 0.7 V), Vavg ≈ (20 - 0.7)/π ≈ 6.14 Vdc.

Question 9

Why is the bridge rectifier used more commonly than the full-wave rectifier?
A) It does not require the use of a center-tapped transformer.
B) With equal input voltages, the bridge rectifier provides a higher dc output voltage.
C) The bridge rectifier can be directly coupled to an ac line input.
D) All of the above.

Accepted Answer

Bridge rectifiers are more commonly used than full-wave rectifiers because they do not require a center-tapped transformer, they provide a higher DC output voltage with equal input voltages, and they can be directly coupled to an AC line input.

Question 10

-What is the total current that is being drawn through RS in Figure ?
A) 6.06 mA
B) 3.3 mA
C) 2.76 mA
D) 2.15 mA

Accepted Answer

The answer of

-What is the total current that...

Question 11

Which of the following will reduce the ripple in the output from a filtered rectifier?
A) Increasing the value of the filter capacitor.
B) Increasing the load resistance.
C) Adding a zener voltage regulator.
D) All of the above.

Accepted Answer

All the options listed contribute to reducing the ripple in the output from a filtered rectifier. Increasing the value of the filter capacitor allows it to store more charge, thus smoothing out the variations in the output voltage more effectively. Increasing the load resistance reduces the current draw from the filter capacitor, allowing it to maintain a more constant voltage. Adding a zener voltage regulator stabilizes the output voltage by providing a constant voltage regardless of variations in the input voltage or load conditions.

Question 12

A 22 μF filter capacitor is connected to a half-wave rectifier. If the value of the capacitor is increased to 100 μF, the ripple in the circuit output will
A) increase.
B) decrease.
C) remain the same.

Accepted Answer

Increasing the capacitance of the filter capacitor in a rectifier circuit decreases the ripple voltage, leading to a smoother output.

Question 13

The basic power supply is made up of
A) a regulator, a follower, and a rectifier.
B) a filter, a follower, and a regulator.
C) a rectifier, a filter, and a regulator.

Accepted Answer

A basic power supply converts AC to DC power and typically consists of a rectifier (to convert AC to DC), a filter (to smooth out the DC signal), and a regulator (to provide a constant DC output).

Question 14

The most commonly used type of rectifier is the
A) half-wave rectifier.
B) full-wave rectifier.
C) bridge rectifier.

Accepted Answer

The bridge rectifier is the most commonly used type of rectifier due to its efficiency in converting alternating current (AC) to direct current (DC) using both halves of the AC waveform, unlike half-wave and full-wave rectifiers that are less efficient or more complex in design.

Question 15

A full-wave rectifier has a 9.3 Vpk output and a 4.7 kΩ load resistance. What is the dc load current for the circuit?
A) 1.26 mA
B) 2.61 mA
C) 629.8 μA
D) 1.4 mA

Accepted Answer

The dc load current is equal to the peak output voltage divided by the load resistance. In this case, the peak output voltage is 9.3 Vpk and the load resistance is 4.7 kΩ, so the dc load current is 9.3 Vpk / 4.7 kΩ = 1.98 mA.

Question 16

A voltage regulator
A) maintains a constant power supply dc output voltage.
B) steps up or steps down the line voltage.
C) reduces the variations in ac line voltage.
D) Both A and C above.

Accepted Answer

The answer of A voltage regulator
A) maintains a constant power...

Question 17

A negative half-wave rectifier eliminates the alternations of the transformer output.
A) positive
B) negative

Accepted Answer

A negative half-wave rectifier eliminates the positive alternations of the transformer output, allowing only the negative half-cycles to pass through.

Question 18

In the schematic for a half-wave rectifier , the diode points toward the ungrounded side of the load. The output from the rectifier is
A) positive.
B) negative.
C) either positive or negative, depending on the polarity of the transformer secondary voltage.

Accepted Answer

In a half-wave rectifier, the diode allows current to flow only in one direction. When the diode points toward the ungrounded side of the load, it means that during the positive half-cycle of the AC input, the diode will be forward-biased and allow current to flow, resulting in a positive output voltage across the load.

Question 19

A bridge rectifier has values of V1 = 120 Vac, turns ratio = 5:1, and RL = 500 Ω. What is the dc output voltage?
A) 14.4 Vdc
B) 7.19 Vdc
C) 20.8 Vdc
D) 22.6 Vdc

Accepted Answer

The dc output voltage is given by:Vdc = (V1 * turns ratio) / (π * RL)Vdc = (120 Vac * 5) / (π * 500 Ω)Vdc = 20.8 Vdc

Question 20

When troubleshooting a rectifier, it is important to check every diode in the rectifier.

Accepted Answer

The answer of When troubleshooting a rectifier, it is important...

Quiz 3: Common Diode Applications: Basic Power Supply Circuits

. For the transformer shown, which current and voltage have the greatest values?

A positive full-wave rectifier has a secondary voltage of 20 Vpk. The peak load voltage for the circuit is

A rectifier is used to

The term leaky is used to describe a capacitor that is

The term full load means

-When testing a basic power supply, you see that the primary fuse is blown. This typically indicates that

A filtered half-wave rectifier has a peak secondary voltage of 20 Vpk. The PIV rating for any diode in the circuit must be at least

A half-wave rectifier is connected to a transformer with a secondary voltage of 20 Vpk. The average output voltage is

Why is the bridge rectifier used more commonly than the full-wave rectifier?

-What is the total current that is being drawn through RS in Figure ?

Which of the following will reduce the ripple in the output from a filtered rectifier?

A 22 μF filter capacitor is connected to a half-wave rectifier. If the value of the capacitor is increased to 100 μF, the ripple in the circuit output will

The basic power supply is made up of

The most commonly used type of rectifier is the

A full-wave rectifier has a 9.3 Vpk output and a 4.7 kΩ load resistance. What is the dc load current for the circuit?

A voltage regulator

A negative half-wave rectifier eliminates the alternations of the transformer output.

In the schematic for a half-wave rectifier , the diode points toward the ungrounded side of the load. The output from the rectifier is

A bridge rectifier has values of V1 = 120 Vac, turns ratio = 5:1, and RL = 500 Ω. What is the dc output voltage?

When troubleshooting a rectifier, it is important to check every diode in the rectifier.