Static Electricity

Question 1

What is an elctrostatic precipitator

Answer 1

Coal burning power stations produce huge amounts of smoke pollinations which is removed through static electricity . Thin wires are stretched across the centre of the chimney and charged positively. The gas around them becomes positively charged and are then repelled by the wires towards earthed metal plates where the dust sticks a mechanical hammer hits the plate every few miniutes and the ash falls into a bin

Question 2

How does paint spraying work

Answer 2

The nozzle is charged positively, the droplet of paint are then repelled by each other so the paint spreads out to form a large even cloud. The droplets. Of paint are then attracted to the negatively charged object.

Question 3

Cellulose acetate

Answer 3

Positively Chatged when rubbed . Insulator

Question 4

Polythene

Answer 4

Becomes negatively charged when rubbed . Insulator

Question 5

Sharp points

Answer 5

Loose charge easily. Used in lightning conductor

Question 6

Gold leaf electroscope is used for

Answer 6

Detecting charge

Question 7

Charges are measured and stored in

Answer 7

Measures in Columbs stores in capacitators

Question 8

Conductors allow

Answer 8

Electrons to move through them , insulators do not

Question 9

What can be made to conduct

Answer 9

Any insulating materials can be made to conduct if voltage is high enough eg lightning and air

Question 10

What does the charging process do

Answer 10

Transfers electrons

Question 11

What is static electricity caused by

Answer 11

Frictions

Question 12

Why does water bend away from negatively charged rod

Answer 12

Electrons in water are repelled and it becomes positive and bends to the rod

Question 13

What is lightning

Answer 13

Thunderclouds discharging their electricity

Question 14

How can insulating materials be given charge

Answer 14

By being rubbed

Question 15

Why does hair stand up when you palace your hand on the van de graaf generator

Answer 15

Charge flows from the Dome to all parts of her body . The pieces of hair are then repelled by each other . The girl stands on an insulator to avoid the Charge escaping through her body and into the earth

Question 16

How is it possible for a charged object to attract something that is uncharged

Answer 16

Charging by induction e.g negatively charged balloon brought near the wall negative charges are repelled in the wall and the balloon sticks to the wall as it is attracted to the positive charge . Same with paper. Negative charges are repelled from the paper and the paper then sticks to the negatively charged rod.

Question 17

How come charging by induction works

Answer 17

Because attractive forces are stronger than repulsive forces

Question 18

What is the issue with pipes and static electricity

Answer 18

When a road tanker pipes oil or petrol into a storage tank , the connecting pipe must be earthed if it isn’t the pipe could become charged . A build up of charge would cause a spark . This could cause an explosion As the fuel vapour Reacts with oxygen in the air .

Question 19

Why do hospitals need anti static floors

Answer 19

Some of the gases are explosive . If the gas escapes into the air a tiny spark could make it explode . To eliminate static charge in operating theatres antistatic material is used for the flor

Question 20

What does the gold leaf electroscope consist of

Answer 20

It detects electric charge . Metal plate at the top is connected to the metal rod inside the instrument but insulated from the rest of ye apparatus . Metal rod has a gold leaf attached to it.

Question 21

Why is the leaf made of gold

Answer 21

Gold can be beaten into very thin sheets

Question 22

How does the gold leaf electroscope work

Answer 22

It is used to investigate charge on different objects . The electroscope is charged by bringing a positively charged rod close to it , this attracts negative charges towards the metal plate leaving a positive charge on the metal rod and the gold leaf . The leaf is repelled from the rod and rises

Question 23

How do u Earth the electroscope

Answer 23

Touch it with your finger and excess charge flows through your finger to the earth

Question 24

Why is the rubber hose of a Petrol can can made of conducting rubber

Answer 24

If the rubbers a conductor charge flows away and will not cause a spark

Question 25

Why do sharp points loose charge easily

Answer 25

Charge the air . Point at the top of the Lightning conductor lossss electricity to the clouds to neutralise their charge

Question 26

How does nylon clothing become charged

Answer 26

Charged by frictions of rubbing against your body when you remove the clothes they crackle because of the Sparks of static electricity escaping to the earth

Question 27

Why do you get a shock after walking on nylon carpet and touching a conductor

Answer 27

You’ve been charged by frictions and the shock is from the charge escaping from you to the conductor

Question 28

How do ink jet printers work

Answer 28

Inkjet. Directs a fine jet of ink drops onto paper. Each spot of ink is given a charge so that as it falls between a pair of deflecting plates with the opposite charge , electrostatic forces direct it to the correct position. The charges on the plates change hundreds of times each second so that each drop falls in a different position, phoning pictures and words on the paper as required

Question 29

How do photocopiers work

Answer 29

Positive charges are sprayed onto a rotating drum whose surface is coated with a metal called selenium . A bright light is shone onto the sheets of paper to be copied . The white parts of the paper reflect light onto the drum and the dark or printed places do not. Selenium losses it’s charge when light is reflected onto it . A fine negatively charged carbon powder called toner sticks to the charged parts of the drum . A sheet of paper is pressed against the drum and picks up the pattern of the carbon powder. The powder is then fixed in palace by a heater.

Question 30

What is the issue with aircraft and static electricity

Answer 30

As aircraft fly through the air they become charged with static electricity there is high potential that a spark is caused during refilling when the charge escapes go the earth , this could cause an explosion. A solution to this problem is to Earth the plane as soon as it lands before refuelling fuel tankers just be earthed before any fuel is transferred to prevent sparks causing a fire or explosion

Question 31

What is the issue with television screens and computer monitors

Answer 31

They become charged with static electricity as they are used . These charges attracts light uncharged particles that is dust

Question 32

What is wrong with clothing and static electricity

Answer 32

Our clothing under certain circumstances become charged with static electricity when we remove the clothes there is a possibility of receiving a small electric shock as the charge escapes to the earth