Electrical Circuits

Question 1

driving force that pushes charged carriers to flow

Answer 1

electromotive force

Question 2

the amount of energy required to push a coulomb of charge

Answer 2

voltage

Question 3

flow of charge

Answer 3

current

Question 4

opposition to the flow of charges

Answer 4

resistance

Question 5

ohm’s law states that?

Answer 5

current in a circuit is directly proportional to the voltage and inversely proportional to the resistance

Question 6

two terminal variable resistor

Answer 6

rheostat

Question 7

three terminal variable resistor

Answer 7

potentiometer

Question 8

rate per unit time at which electrical energy is transferred

Answer 8

electrical power

Question 9

unit which describes the amount of energy or work transferred per unit time

Answer 9

watt, J/s

Question 10

form of energy resulted from the movement of electrical charge

Answer 10

electrical energy

Question 11

Kirchoff’s 1st law?

Answer 11

Kirchoff’s Current Law, the net total of current entering and exiting a node is equal to 0

Question 12

Kirchoff’s 2nd law?

Answer 12

Kirchoff’s voltage law, the sum of all voltages in a mesh loop / closed path is equal to 0

Question 13

application of KVL to analyze a circuit

Answer 13

Mesh Analysis

Question 14

application of KCL to analyze a circuit

Answer 14

Nodal Analysis

Question 15

steps for thevenin analysis?

Answer 15

• open the load
• get the voltage across the load
• convert sources (short voltage, open current)
• get thevenin resistance
• get thevenin circuit

Question 16

steps for norton analysis?

Answer 16

• short the load
• get the current passing through the shorted load
• convert sources (short voltage, open current)
• get the thevenin resistance
• setup norton circuit

Question 17

passive electrical device that transfers electrical energy from one electrical circuit to another through induction

Answer 17

transformer

Question 18

in power electronics, the device used to turn ac to dc

Answer 18

rectifier

Question 19

in power electronics they are used to turn dc to ac

Answer 19

inverter

Question 20

used to increase the or decrease the magnitude of dc?

Answer 20

chopper

Question 21

chopper that increases dc?

Answer 21

boost chopper

Question 22

chopper that decreases dc?

Answer 22

buck chopper

Question 23

a current that is constantly changing in amplitude and direction

Answer 23

alternating current

Question 24

most common type of ac waveform?

Answer 24

sinusoidal wave

Question 25

height of an ac waveform which changes over time

Answer 25

amplitude

Question 26

height of an ac waveform measured from the 0 mark to the highest point

Answer 26

peak amplitude

Question 27

total height of a waveform from the maximum negative to the maximum positive

Answer 27

peak to peak amplitude

Question 28

mathematical mean of all waveforms points over the period of one cycle

Answer 28

average amplitude

Question 29

way of expressing an ac voltage or current in terms of functionally equivalent to dc

Answer 29

rms amplitude

Question 30

what does rms stand for?

Answer 30

root mean square

Question 31

dc equivalent of an ac?

Answer 31

root mean square amplitude

Question 32

ratio between the rms and the average amplitude?

Answer 32

form factor

Question 33

ratio between the peak value and the rms?

Answer 33

crest factor

Question 34

it is a property of a ______ to oppose ac. it has the ability to block high frequencies.

Answer 34

inductor, inductive reactance

Question 35

it is a property of a ______ to oppose ac. it has the ability to block low frequencies.

Answer 35

capacitor, capacitive reactance

Question 36

total opposition to the flow of ac

Answer 36

impedance

Question 37

impedance is a combination of?

Answer 37

resistances and reactances

Question 38

what is the basis when talking about leading and lagging power factor?

Answer 38

the current

Question 39

when the current lags, the power factor ______

Answer 39

lags

Question 40

when the current leads, the power factor ______

Answer 40

leads

Question 41

when the current lags, the load is?

Answer 41

inductive

Question 42

when the current leads, the load is?

Answer 42

capacitive

Question 43

power factor formula?

Answer 43

cos theta

which is also equal to resistance over impedance

Question 44

reactive factor formula?

Answer 44

sin theta

which is also equal to reactance over impedance

Question 45

aside from the angle of load impedance, what does the theta represent?

Answer 45

phase difference between the current and voltage

v-c
if positive, current and pf is lagging
if negative, current and pf is leading

Question 46

positive impedance angle means?

Answer 46

inductive load

Question 47

negative impedance angle means?

Answer 47

capacitive load

Question 48

frequency when current is nether lagging nor leading

Answer 48

resonance frequency

Question 49

value of reactance at resonance frequency?

Answer 49

zero

Question 50

phase angle at resonance?

Answer 50

zero

Question 51

what do you call power given that the frequency is at resonance? unit?

Answer 51

true power, watts

Question 52

what is the phase angle when the load is purely reactive?

Answer 52

purely inductive, 90 degrees
purely capacitive, -90 degrees

Question 53

what do you call the power given phase angle of positive or negative 90? unit?

Answer 53

reactive power, volts amps reactive (var)

Question 54

what do you call the power given an impedance? what’s the unit?

Answer 54

apparent power, volt-ampere (va)