P3.1 Static And Charge

Question 1

Ampere (A)

Answer 1

Unit for current

Question 2

Battery

Answer 2

1 or more cells

Question 3

Cell (electricity)

Answer 3

Device producing potential difference (separation of charge) from chemical reactions

What people normally call a ‘battery’

Question 4

Conventional current

Answer 4

Opposite to regular current
Current flows from positive to negative, opposite to electron flow
Electrons come from positive terminal of cell and go towards negative terminal

USED IN CIRCUIT DIAGRAMS

Question 5

Coulomb (C)

Answer 5

Unit for charge

Question 6

Electric current

Answer 6

Rate of flow of charged particles (usually electrons)
current = charge / time

Question 7

Electric charge

Answer 7

Property (like mass) of a particle
Can be positive or negative

Question 8

Electric field

Answer 8

Region produced by charged particles or objects,
where charged particles of objects experience a force

Question 9

Milliamp (mA)

Answer 9

Milli = / 1000
1mA = 1 / 1000 amps

Question 10

Spark

Answer 10

Breakdown of air that discharges charged object
Heating of the air produces light and sound
Rapid discharge of excess electrons back to earth

Question 11

Static electricity

Answer 11

Charge that insulating objects acquire because of transfer of electrons
Obiects can be charged by transferring electrons to/from them, by force of friction simply by rubbing
Only insulated materials/objects can become charged. An insulated material is one which doesn’t allow electrons to move through it
Which material gains/loses electrons depends on the 2 materials being rubbed

Question 12

Material has to be this if it is to become charged when you rub it

Answer 12

Insulator - does not conduct electrical charge

Question 13

Objects become charged when these subatomic particles are transferred

Answer 13

Electrons

Question 14

Why an electrostatic precipitator works

Answer 14

Dust particles travel through a metal grid and become either positively or negatively charged
Charged dust particles are attracted to plates that are either earthed or have the opposite charge to the dust
Dust sticks to plates inside the chimney and then falls down, it does not leave the chimney

Question 15

_____ can be removed from chimney smoke using a _____ metal grid to charge up the dust. The dust is then _____ to charged or earthed metal plates on the sides of the chimney and then falls down into a collector.

Answer 15

dust, charged, attracted

Question 16

If you need to spray a car with paint you can charge the spray gun and the car with ________ charges.
This means that the paint will be _____ to the car and little paint will be lost. Also, the paint will get onto parts of the car that are difficult to reach, making the coat more even.

Answer 16

opposite, attracted

Question 17

When paramedics are trying to restart someone’s heart with a _____, they make sure that the paddles are _____ and that there is good _____ contact with the patient’s chest.
When the _____ passes through the heart, it makes the heart contract and start beating again. It is important that the paramedics, or other people, do not receive a shock, so the handles of the paddles are _____.

Answer 17

defibrillator, charged, electrical, charge, insulated

Question 18

One of the easiest methods is to connect to earth through a _____.

Answer 18

Wire

Question 19

Anti-static liquids, sprays, and cloths contain something that _____ electricity.

Answer 19

Conduct

Question 20

Both aircraft and fuel trucks are connected to _____ before refuelling starts.

Answer 20

Earth

Question 21

People working with electrical components use a wrist band containing a _____ connected to earth.

Answer 21

Wire

Question 22

Electrostatics are used in paint spraying. Put the sentences in the correct order
to explain the process.

a) The spray is attracted to the negative object.
b) This is because the charged spray particles repel each other and spread out.
c) The particles form a thin, even paint layer on the object.
d) As the spray leaves the nozzle it becomes positively charged.

Answer 22

d, a, c, b

Question 23

A cloth is rubbed over a balloon leaving the balloon negatively charged.
Which of the following statements are true?

a) The balloon lost positive charges.
b) There is an electric field around the balloon.
c) The cloth is now positively charged.
d) The cloth transferred negative charges to the balloon.

Answer 23

b, c, d

Question 24

Battery cell diagram

Answer 24

⁺| ⁻ı

Question 25

Equation for charge flow

Answer 25

Charge flow(C) = current(A) x time(s)