Ch 13 - Electrical System

Question 1

The parts of an electrical system are called ____.

Answer 1

electrical components!

Question 2

The main components of an electrical system:

Answer 2

• cell (battery)
• wires
• electrical device (eg bulb)

Question 3

Closed circuit provides …

Answer 3

…a continuous path for electric current to flow.

Question 4

Open circuit occurs when…

Answer 4

…there is a gap in the circuit and electricity cannot flow from one end of the cell to the other.

Question 5

Electrical appliances can work in a ____ circuit.

Answer 5

CLOSED

Question 6

Electrical appliances cannot work in an ____ circuit.

Answer 6

OPEN

Question 7

How many paths in a series circuit?

Answer 7

There is only ONE path through which electricity can flow through.

Question 8

How many paths in a parallel circuit?

Answer 8

There are SEVERAL paths through which electricity can flow through.

Question 9

Define electric current.

Answer 9

a measure of the rate of flow of electric charge through a conductor.

Question 10

SI unit of Electric Current?

Answer 10

ampere (A)

Question 11

Conventional Current
vs.
Electron Flow

Answer 11

positive to negative
&
negative to positive

Question 12

How to measure electric current?

Answer 12

Ammeter

Question 13

How to connect an ammeter?

Answer 13

In series arrangement!

Question 14

Define potential difference.

Answer 14

the amount of energy needed to move one unit of electric charge from one point to another

Question 15

Potential difference is also v____.

Answer 15

voltage!!!

Question 16

SI unit of potential difference/voltage?

Answer 16

volt (V)

Question 17

How to measure potential difference?

Answer 17

voltmeter

Question 18

How to connect voltmeter?

Answer 18

In parallel arrangement :)

Question 19

Define resistance.

Answer 19

A measure of the degree to which an electrical component opposes the flow of electric current.

Question 20

SI unit of resistance.

Answer 20

ohm (Ω)

Question 21

How to find resistance (using voltage and current)?

Answer 21

R = V/I

Question 22

Types of resistors.

Answer 22

• fixed resistors
• variable resistors (rheostats)

Question 23

Uses/examples of rheostats.

Answer 23

• light dimmer
• volume control on music player
• speed control of a model train

Question 24

Formula of resistance in a series circuit. (use R)

Answer 24

RT = R1+R2

Question 25

In series circuit, the effective resistance is always _____ than the largest of the individual resistances.

Answer 25

GREATERRR 👀

Question 26

Formula of resistance in a **parallel** circuit. (use R)

Answer 26

1/RT = 1/R1 + 1/R2

Question 27

In parallel circuit, the effective resistance is always _____ than the smallest of the individual resistances.

Answer 27

SMALLER 🤏

Question 28

The 3 effects of an electric current??

Answer 28

* chemical effect 🧪 * magnetic effect 🧲 * heating effect 🔥

Question 29

Use of chemical effect of electric current?

Answer 29

electrolysis and electroplating

Question 30

What is electrolysis?

Answer 30

When electricity is used to break down compounds into its elements.

Question 31

Examples of electrolysis.

Answer 31

aluminium from bauxite

Question 32

What is electroplating?

Answer 32

coating objects in metal 😂

Question 33

Metals that are used for electroplating?

Answer 33

copper, chromium, silver, gold, nickel

Question 34

To **increase the strength** of magnetic effect:

Answer 34

* Increase the number of turns of the wire (solenoids) * Increasing the current

Question 35

Examples of magnetic effect used in real life.

Answer 35

* magnetic cranes * **electric bells** * electric motors (vacuum cleaners and fans)

Question 36

In heating appliances, the heating element is made of materials with _____ resistance.

Answer 36

HIGHHH HEE HEE

Question 37

Examples of materials with high resistance.

Answer 37

nichrome (alloy of nickel), iron, chromium

Question 38

1 kW = ______ W ?

Answer 38

1 kW = 1,000 W

Question 39

Define power.

Answer 39

The amount of electrical energy converted to other forms of energy per second by the component.

Question 40

SI unit of power?

Answer 40

watt (W)

Question 41

Unit used to measure amount of electricity used **in homes**.

Answer 41

kilowatt-hour (kWh)

Question 42

Formula for energyy

Answer 42

energy = power x time

Question 43

Formula for power

Answer 43

power = energy / time

Question 44

2 electric hazards

Answer 44

electrical fire & electric shock

Question 45

What can **cause** electrical fire?

Answer 45

* short circuit * overloading

Question 46

What can **cause** electric shock?

Answer 46

* damaged insulation * wet conditions

Question 47

**2 safety feature** found in household electric circuits

Answer 47

fuse & circuit breaker

Question 48

fuse VS. circuit breaker

Answer 48

must be replaced after used VS. needs to be reset after use