Topic 11

Question 1

Earthing

Answer 1

an excess amount of electrons flows through a conductor and dissipates into the ground preventing the build up of charge stopping a spark from happening.

Question 2

what causes lightning

Answer 2

Static charge builds up in clouds due to friction. Eventually, the electrical potential energy is large enough that it jumps to a nearby object of the opposite charge.

Question 3

electrical field

Answer 3

defined as the electrical force per unit charge. radially outward from a positive charge and radially inward for a negative charge EFPUC

Question 4

hazards of spark

Answer 4

can cause an explosion

Question 5

negatively charged balloon near hair

Answer 5

the balloon is an insulator and is rubbed (friction) against the hair so electrons are transferred, making it negatively charged. Opposite charges attract, so the neutral hair will move the protons towards the balloon.

Question 6

like charges

Answer 6

repell

Question 7

unlike charges

Answer 7

attract

Question 8

Why are insulators better than conductors for shocks

Answer 8

Insulators are the best material as they build up the most charge easier than conductors

Question 9

why do we get shocks from everyday objects

Answer 9

We build up charge when cold air and rubbing clothes or wearing slippers or rubbing foot on carpet (friction) , so when you touch a metal object like a doorknob, you feel a spark and hear a spark as the electrons jump to the object as unlike charges attract.

Question 10

electrostatic charges in spaypaint

Answer 10

• paint particles are charged so will repel covering a larger surface area
• smooth thin layer
• wastes less paint

Question 11

bonding line

Answer 11

a cord of conducting materials which allows electrons to flow through it
- used when planes are getting refueled

Question 12

printer

Answer 12

-the drum of the printer is positively charged
-the laser sends a message to the drum where it should be negatively charged
- the paper is positively charged
- powder will only go in places that are negatively charged

Question 13

how can buildings be protected from lightning

Answer 13

metal lightning rods
- earth tall buildings

Question 14

field between two parallel plates

Answer 14

this is called a uniform electric field because the field is the same everywhere + equal spacing

Question 15

electrostatic field lines

Answer 15

electric fields are sometimes called electrostatic field lines
- show were the field is strongest (where the field lines are closest)
- always go from + charged object to - charged object

Question 16

Explain how rubbing the comb with a dry cloth gives the comb a positive electric charge

Answer 16

friction, electronds transfered, e=negative chnage , keaving more protons

Question 17

Explain how the positively-charged plastic comb picks up the small pieces of paper

Answer 17

a negative change insuced on teh side of the comb, opposites attarct

Question 18

A student has a bar magnet, a piece of iron the same size as the magnet, and
some paper clips.
Describe how the student could use these items to demonstrate temporary
induced magnetism.