Keywords and formulas

Question 1

(wheatstone bridge) what does R1/R2 equal to?

Answer 1

R3/R4

Question 2

What does R1 equal to in the delta to wye transformation

Answer 2

(RaxRb)/(Ra+Rb+Rc)

Question 3

What does R2 equal to in the delta to wye transformation

Answer 3

(RaxRc)/(Ra+Rb+Rc)

Question 4

What does R3 equal to in the delta to wye transformation

Answer 4

(Ra+Rb)/(Ra+Rb+Rc)

Question 5

What is an essential node?

Answer 5

A node where 3 or more elements join

Question 6

What is a node?

Answer 6

A point where two or more circuit elements join

Question 7

What is a path?

Answer 7

A trace of adjoining elements where no elements included more than once

Question 8

What is a branch?

Answer 8

A path which connects two essential nodes.

Question 9

What is an essential branch?

Answer 9

A path which connects two essential nodes without passing through any other essential nodes.

Question 10

What is a loop?

Answer 10

A path whose last node is the same as the starting node

Question 11

What is a mesh?

Answer 11

A loop that does not enclose any other loops

Question 12

What is a Planar circuit?

Answer 12

A circuit that can be laid out on a plane iwht no crossing branches

Question 13

What does Rth equal?

Answer 13

(Voc)/(Isc)

Question 14

What load of resistance will give rise to maximum power transfer into the load?

Answer 14

The same amount of resistance as Rth

Question 15

Does a Thevenin equivalent circuit include a resistor in parallel or in series?

Answer 15

In series

Question 16

Does a Norton equivalent circuit include a resistor in parallel or in series?

Answer 16

In parallel

Question 17

What are capacitors?

Answer 17

• Capacitors store energy in the form of electric charge
• Capacitors oppose the change in voltage across their terminals
• Change in voltage across the plates causes current to flow through the capacitor.

Question 18

What is the formula for the voltage across a capacitor when discharging

Answer 18

Vc=Voexp(-t/RC)

Question 19

What is the formula for voltage across a capacitor when charging

Answer 19

Vc=Vf[1-ecp(-t/RC)]

Question 20

What are inductors

Answer 20

• An inductor stores energy in the form of a magnetic field surrounding its coil
• Inductors oppose the change in current through their terminals (or coil)
• Change in current causes voltage to be developed across the inductor terminals (due to magnetic flux)

Question 21

whats the time constant of a Resistor-Inductor circuit

Answer 21

L/R

Question 22

Is a diode a semiconductor

Answer 22

yes

Question 23

what are diodes commonly used for?

Answer 23

rectification- turning AC into DC

Question 24

What do diodes do to current?

Answer 24

they only allow current to flow in one direction

Question 25

What is the forward voltage drop of silocon

Answer 25

0.7v

Question 26

What is the forward voltage drop of Germanium

Answer 26

0.3v

Question 27

What is the forward voltage drop of Gallium Arsenide

Answer 27

1.8v

Question 28

What do zener diodes do

Answer 28

breakdown safely under reverse bias conditions

Question 29

What is breakdown voltage also known as

Answer 29

Zener voltage

Question 30

What do you do to semi conductors to turn them into p-type and n-type materials

Answer 30

dope them

Question 31

How are diodes made

Answer 31

the fusion of a PN junction

Question 32

what type of IV curves do diodes have

Answer 32

non linear

Question 33

What does a sinusoid signal v(t) equal to

Answer 33

Vmsin(wt+%)

Question 34

What is the phasor transform formula?

Answer 34

v(t)=Re(Vexpjwt)

Question 35

What are the phasor relationships for capacitors and inductors

Answer 35

current leads voltage by 90 degrees (capacitors) | inductors- voltage leads current by 90

Question 36

Z?

Answer 36

V/I

Question 37

resistance?

Answer 37

/z/cos%

Question 38

Y?

Answer 38

1/z

Question 39

Conductance?

Answer 39

/Y/cos%

Question 40

suceptance?

Answer 40

/Y/sin%

Question 41

Why are bipolar junction transistors usefull?

Answer 41

small curents can be used to controll much larger ones

Question 42

what are the 2 different types of transistor?

Answer 42

PNP NPN

Question 43

What are the 3 terminal devices

Answer 43

collector base emitter

Question 44

What are the characteristics of an ideal voltage amplifier

Answer 44

Av=infinity Ri=infinity Ro=0 They are differential amplifiers

Question 45

Application of negative feedback

Answer 45

Negative feedback is commonly used in op amp circuits to reduce the gain and improve the properties of the amplifier.

Question 46

What is the repercussion of the gain being assumed to be fininte? (non inverting amplifier)

Answer 46

V-=V+=Vi

Question 47

equation of vi in a non inverting amplifier?

Answer 47

Vo x (R2)/(R1+R2)

Question 48

What is the result of assumed infinte gain on a inverting amplifier?

Answer 48

V-=V+=0

Question 49

What is V- called in a inverting amplifier?

Answer 49

Virtual earth

Question 50

Formula for G? (non inverting)

Answer 50

[Vo/Vi]=[R1+R2/R2]

Question 51

Formula for G? (Inverting)

Answer 51

[Vo/Vi]=-(R1/R2)

Question 52

What does an inverting Summing amplifier do?

Answer 52

it is used to add up0 a number of voltages as in superposition

Question 53

formula for Vo in a inverting summing amplifer?

Answer 53

Vo=-V1(R1/R2)-V2(R1/R3)

Question 54

What does a differential amplifier do?

Answer 54

A differential amplifier can be used to amplify the differences between two voltages

Question 55

What is the formula for Vo for a differential amplifer?

Answer 55

Vo=(V1+V2)R1/R2

Question 56

What are the benefits of negative feedback on Op Amps

Answer 56

Negative feedback reduces gain get more consistency easy analysis