Rectifiers Part A

Question 1

What is the purpose of a free wheeling diode?

Answer 1

• To aid in the suppression of inductive kick

Question 2

The process of changing alteration current (ac) power to direct current (dc) power is?

Answer 2

Recitification

Question 3

A device that changes ac to dc is?

Answer 3

Rectifier

Question 4

2 types of rectifiers are?

Answer 4

Half wave rectifiers and full wave rectifiers

Question 5

The pulsating dc voltage at the load has a?

Answer 5

Ripple frequency

Question 6

Time for one complete cycle of the load voltage is the same as the time for one cycle of the supply voltage. True or false?

Answer 6

True

Question 7

Reverse biased diode is like a?

Answer 7

Open switch

Question 8

Forward biased diode is like a

Answer 8

Closed switch

Question 9

What is dc?

Answer 9

It’s current that flows in only one direction. Dc current is always in the same direction and the polarity doesn’t change.

Question 10

What is ac current?

Answer 10

Alternating current. It can periodically reverse direction, and can also reverse polarity.

Question 11

What is a sine wave?

Answer 11

A sine wave graphically represents how the value of an ac current or voltage change over a period.

Question 12

What is an electrical cycle?

Answer 12

It describes how currents or voltages vary through one complete set of values.

Question 13

Define double subscription notation

Answer 13

It’s used when you need to determine the polarity of one point in a circuit with respect to a second point in a circuit

Question 14

What is a resistor?

Answer 14

Resistance is an opposition to current flow by an electric circuit.

Question 15

What are the 2 types of resistors?

Answer 15

Fixed
Variable

Question 16

What is a capacitor?

Answer 16

It is a component in an electronic circuit that can store and release an electrical charge called capacitance, which causes opposition to change in voltage.

Question 17

What are the types of capacitors?

Answer 17

Paper
Plastic
Film
Mica
Ceramic
Electrolytic
Tantalum

Question 18

Calculate resistors in series and parallel

Answer 18

Series - Rt = R1+ R2…

Parallel - 1/Rt = 1/R1 + 1/R2…

Question 19

Calculate capacitive reactance in series and Parallel

Answer 19

Series - Xct = Xc1 + Xc2…

Parallel - 1/Xt = 1/Xc1 + 1/Xc2…

Question 20

What is an inductor?

Answer 20

An inductor opposes a change in current

Question 21

Calculate capacitive reactance

Answer 21

Xc = 1 devided by (2 times pie times frequency times capacitance)

Question 22

What does an oscilloscope do?

Answer 22

It displays a graph of voltage over time

Question 23

What 2 things does an oscilloscope graph display?

Answer 23

Voltage

Time

Question 24

The characteristic that are common to good conductors is that they possess?

Answer 24

One, two or three valance electrons

Question 25

Elements that have 5 to 8 valance electrons can behave as?

Answer 25

Insulators

Question 26

How many valance electrons do semi conductors have?

Answer 26

4

Question 27

What does a diode do?

Answer 27

It allows current to flow in one direction and prevents current flow in the opposite direction.

Question 28

Parts of a diode are the?

Answer 28

Anode (A) - is on the side of the black triangle Cathode (K) - is on the side by the line that looks like a backwards k

Question 29

What are the 3 current ratings of a diode?

Answer 29

Low Medium High

Question 30

On one side of the diode is a white stripe. Is that white stripe side the cathode or the anode

Answer 30

Cathode

Question 31

What type of diode is this

Answer 31

Hockey puk

Question 32

What type of diode is this?

Answer 32

Power module

Question 33

What type of diode is this?

Answer 33

Stud mount

Question 34

What type of diode is this

Answer 34

Axial type

Question 35

What makes N-type material?

Answer 35

Doping silicon with 5 valence electrons

Question 36

What makes p-type material?

Answer 36

Doping silicon with impurities with the valance electrons

Question 37

What is photo conduction?

Answer 37

It's the property of a material that exhibits a lower resistance when exposed to light energy.

Question 38

At room temperature the barrier potential for germanium PN junction is approximately ___ v?

Answer 38

0.3

Question 39

At room temperature the barrier potential for a silicon PN junction is approximately ___ v?

Answer 39

0.7

Question 40

The ideal reverse resistance of a silicon diode is infinity. In practicle terms it is approximately ___ mega ohms.

Answer 40

30

Question 41

In a diode the lead connected to the p-type material is called a ____? The lead connected to the n-type material is called a ____?

Answer 41

Anode Cathode

Question 42

Light emitting diodes have a forward current of?

Answer 42

15ma - 30ma

Question 43

Where in a cct must a free wheeling diode be placed in order to perform is intended purpose?

Answer 43

In parallel with an inductive load.

Question 44

A diode offers a high resistance when it's reverse biased? True or false?

Answer 44

True

Question 45

Heat sinks are typically constructed from?

Answer 45

Aluminum

Question 46

Clamp on ammerters are not very accurate measuring current below?

Answer 46

0.1 amps

Question 47

Photo diodes in a dc cct must be installed forward bias or reverse bias?

Answer 47

Reverse bias

Question 48

When choosing a replacement diode, what does a VRRM rating refer to?

Answer 48

The reverse voltage that a diode can hold back or withstand

Question 49

Which two elements are used as the basic building block for most semiconductor devices?

Answer 49

Silicon and germanium

Question 50

What is shown on the display of an Oscilloscope?

Answer 50

Instantaneous values

Question 51

N type material

Answer 51

Doping silicon with pentravelant materials (material with 5 valence materials)

Question 52

R-type material

Answer 52

Doping silicon with trivalent materials

Question 53

How to find inductance

Answer 53

2 x pie x f x L