Unit 4 Electricity Lesson 6-10

Question 1

How to identify a series circuit vs a parallel circuit

Answer 1

series: electrons flow through one path
parallel: -electrons flow throguh two or more paths - the current splits at a node

Question 2

what do you need to have in a parallel circuit drawing

Answer 2

a node (threesome of wires)

Question 3

what is kirchoffs’s law for a series circuit?

Answer 3

IT= I1 = I2= I3 (current intensity, amps)
VT=V1+V2+V3
Req= R1+R2=R3

Question 4

what is kirchoffs’s law for a parallel circuit?

Answer 4

IT= I1+I2+I3
VT=V1=V2=V3
Req= 1/R1+ 1/R2+1/R3 (flip when solving end product)

Question 5

What does R equal and what are its symbols?

Answer 5

R= V/I
R (resistance)= Ohms (Ω)
V(voltage)=volts (V)
I(current intensity)=amps (A)

Question 6

what is power?

Answer 6

the amount of energy used over a period of time

Question 7

how is power calculated the simpler regular way ? and its units

Answer 7

P=IV
P(power)=watts (W)
I(current intensity)=amps (A)
V(voltage)=volts (V)

Question 8

how is power calculated the other longer ish way? and its units

Answer 8

P=E/T
P(power)=watts (W)
E(energy)=joules (J)
T(time)= seconds (s)

Question 9

what does kWh mean and why

Answer 9

kilowatts per hour to calculate on appliances and hydro bill (human adulting things)

Question 10

how do you get watts to kilowatts?

Answer 10

÷ 1000

Question 11

when doing those word problems with calculating the cost of an apppliances energy you always??

Answer 11

multiply stuff (ex: 21 kWh x 0.08 $ = 1.75 per day)

Question 12

6

list the electrical functions?

Answer 12

1. power supply/source
2. conduction
   3.insulation
   4.control
   5.protection
3. transformation

Question 13

6

list the power supply exemples!!

Answer 13

1. chemical batteries
2. photovoltaie cells (solar panels)
3. alternators
4. thermocouple
5. piezoelectric
6. Electrical outlets

Question 14

what is a power supply?

Answer 14

the electrical function performed by any component that can generate or provide electric current

Question 15

what is conduction?

Answer 15

the electrical function performed by any componenet that can transmit electric current from one part of a circuit to another

Question 16

conductivity varies on what?

Answer 16

based on length, nature of wire, diameter and temperature of conductor

Question 17

exemple of conductors

Answer 17

metals

Question 18

wha is insulation?

Answer 18

the elctrical function performed by any component that prevents an electric current.

Question 19

insulation is often used for what?

Answer 19

to cover wires to protect people from shocks and prevent short circuits

Question 20

exemple of insulators

Answer 20

plastic, rubber, ceramic

Question 21

what is control

Answer 21

the electrical function performed by any component that can open and close a circuit (therefore controlling the flow of electrons)

Question 22

exemple of control

Answer 22

SWITCHES

Question 23

what are the four types of switches? and picture them mentally

Answer 23

1. flip flop (rocker) (those fat wall light switches)
2. lever (the ones in the lab)
3. push button (litteraly a button)
4. magnetic

Question 24

what is unipolar vs bipolar for switches? (picture it in your brain)

Answer 24

unipolar has one path for input and the bipolar has two paths for input

Question 25

what is unidirectional vs bidirectional for switches? (picture it in your brain)

Answer 25

unidirectional is on or off for output while bidirectional is one way or another way for output

Question 26

definition of a lever switch and exemple

Answer 26

controlled by a mechanically moving arm through a small arc ex: light switch

Question 27

definition of a push button and exemple

Answer 27

completes an electric circuit when pressed ex: computer keyboard,doorbell

Question 28

definition for flip flop switch and exemple

Answer 28

on/off switch that rcks (back and forth) when pressed. one side of the switch is raised while the other side is lowered ex: power bar

Question 29

definiton of a magnetic switch and exemple

Answer 29

when the switch is near a magnetic field, two pieces of metal come in contact with each other to close the cirucit and allow the current to pass through it ex:home alarm, doors, windows, power cord on macs

Question 30

what is protection

Answer 30

protection is the electrical function performed by any component that can automatically cut current flow in the event of a power surge

Question 31

if an electrical circuit malfunctions (... or ...) it could cause a .. or ...

Answer 31

(short circuit or overload) fire or electrical shocks

Question 32

what two things can be installed to prevent this from occuring?

Answer 32

fuses and circuit breakers

Question 33

what is the function of a fuse box?

Answer 33

they act as a "weak link" in a circuit, designed to melt and break the cirucit if the current exceeds a safe limit so then a fuse must be replace if it is blown

Question 34

desribe the mechanism of a fuse box and exemple of metal

Answer 34

They contain a thin wire or strip of metal that has a low melting point. When excessive current flows, the metal (lead) heats up rapidly and melts, creating a break in the circuit and stopping the flow of electricity.

Question 35

unlike a fuse a breaker can be ...

Answer 35

RESET

Question 36

how do circuit breakers work?

Answer 36

when the current get too strong, a bimetallic strip becomes hot and bends to disconnect the circuit

Question 37

what is transformation of energy

Answer 37

the electrical function performed by any component that can convert electrical energy into another form of energy

Question 38

give an exemple of transformation of energy

Answer 38

electrical energy to radiation/thermal energy (toaster)

Question 39

function of a diode

Answer 39

- inserted into electrical circuits causing current to flow in one direction

Question 40

what are diodes like

Answer 40

a turnstile (in the metro): a person can exit or enter but not do both

Question 41

what are diodes usually made of

Answer 41

semiconductor material like silicon

Question 42

give two exemples of a diode

Answer 42

1. batter operated devices 2. light emitting diodes (LEDs)

Question 43

what is the drawing for diodes

Answer 43

->I-

Question 44

what is the function of capacitors (condensers)

Answer 44

stores electric charge

Question 45

what is a capacitance

Answer 45

the amount of charge that can be stored

Question 46

what are capacitors compsoed of

Answer 46

two electrical surfaces seperated by an insulating material

Question 47

the charge stored ona capacitor's plate can be...

Answer 47

discharged or charging

Question 48

the current flows from

Answer 48

negative to positive to make the lightbulb shine

Question 49

what is the drawing fro a capacitor

Answer 49

-II-

Question 50

2 exemples of capacitors

Answer 50

1. camera flashes 2. defibrillators

Question 51

what are the 2 fuctions of a transistor

Answer 51

1. Amplifier: they take a small electric current and produce a much bigger current (hearing aids use this function to amply sound) 2. Switch: a small electric current flowing through one part of a transistor can make a much bigger current flow through another part of it. the small current switchs on the larger one (computer chips contain these)

Question 52

what is AC stand for

Answer 52

alternating current

Question 53

what does DC stand for

Answer 53

direct current

Question 54

AC vs DC explain

Answer 54

- in DC, the electrons flow in one direction around a circuit (the voltage remains the same) - while in AC, the direction of electron flow around a circuit is continuously switching

Question 55

what usually generate AC

Answer 55

POWERPLANTS

Question 56

what type of component would be used to convret AC to DC

Answer 56

DIODES

Question 57

batteries produce ... wall sockets produce...

Answer 57

batteries produce DC wall sockets produce AC

Question 58

its easier to transport electricity in

Answer 58

AC across long distances (the voltage is kept high so the current is lower and as a result less energy is lost) transformers convert high to low voltages