Flashcards
Sparks
Cards in this deck (22)
- 1What does an insulating material do?It becomes electrically charged if it is rubbed with another insulating material. This charge is called static electricity.
- 2What does static electricity mean?The electricity stays on the material and does not move. This is due to the transfer of electrons.
- 3What happens to the object that gains electrons and the object that loses electrons?If object gains electrons then it becomes negatively charged.
If object loses electrons the object becomes positively charged. - 4Why are dusting brushes statically charged?The brushes get charged so that they attract dust when they pass over it, making dusting more effective.
- 5Why does synthetic clothing become statically charged and what can this lead to?Can become charged up by friction between the clothing and the person's body as they move and this makes the clothing cling. When the clothing is later removed from the body, static sparks are sometimes produced.
- 6How can a charged object become discharged and how is this process carried out?It can be discharged by earthing it. When an object discharges, electrons are transferred from the charged object to Earth. If you become electrically charged, earthing can result in you getting an electrostatic shock.
- 7How can an electrostatic shock occur when touching a water pipe?Person becomes charged up by friction between soles of their feet and the floor if they are walking on an insulator such as carpet or vinyl. If they then touch the water pipe, the charge is earthed. Discharge occurs, resulting in an electrostatic shock.
- 8What is the danger of static build up?All dangers to static are caused by sparks passing to some flammable (or inflammable) object.
- 9Why do flour mills and petrochemical factories have to be careful with static?They have atmospheres that contain extremely flammable gases or high concentrations of fine particles. A discharge of static electricity in these situations can lead to an explosion, so factories take precautions to ensure no spark is made that could ignite the gases.
- 10Static electricity is also dangerous in any situation where large quantities of charge could flow through your body to earth - e.g. lightning. What are the situations were static can just be a nuisance?It can cause dirt and dust to be attracted to insulators such as TV screens and computer monitors.
It can cause some fabrics to cling to your skin. - 11What happens to electrons when they become really close together?They repel.
- 12What will two insulating materials do if they have the same charge?They will repel each other, e.g. two Perspex rods.
- 13What will two insulating materials with different charges do?They will attract each other, e.g. a Perspex and an ebonite rod.
- 14Explain what happens when objects become electrically charged (static)?Static builds up when electrons are rubbed off one material on to another. The material that receives the electrons becomes negatively charged due to an excess of electrons, while the material giving up electrons becomes positively charged due to a loss of electrons.
- 15What is an ion?An atom or molecule that becomes charged.
- 16What happens if you rub a Perspex rod with a cloth?The Perspex gives up electrons and becomes positively charged. The cloth receives electrons and becomes negatively charged.
- 17What happens if you rub an ebonite rod with fur?The fur gives up some electrons and becomes positively charged, the ebonite rod gains electrons so becomes negatively charged.
- 18How can the chance of receiving an electric shock be reduced?By:
Ensuring that appliances are correctly earthed.
Using insulation mats effectively.
Wearing shoes with insulating soles. - 19What happens to lorries that contain flammable gases, liquids or powders before they are unloaded?They need to be earthed, as friction can cause a build-up of charge. This charge could lead to a spark, which could then ignite the flammable substance.
- 20What things can be used to reduce the problems of static electricity, and how do they work?Anti-static sprays, liquids and cloths can be used. They prevent the transfer of charge from one insulator to another. With no build-up of charge, there can be no discharge.
- 21Why do you connect an aircraft to a fuel tanker when filling up with fuel?The fuel tanker makes sure that any charge built up on the fuel by friction, as it flows through the pipe, flows to Earth, making sure there is no discharge and spark to ignite the fuel.
- 22Why does your hair become static when a balloon is rubbed against your head?Both balloon and head are insulators.
Friction causes electrons to be stripped from one of the objects to the other.
Gain of electrons produce a negative overall charge.
Loss of electrons produce an overall positive charge because there are more protons than electrons.
When balloon and hair are placed together the objects naturally attract as opposites attract.
The hair is splitting apart because it all has negative charge and like charges repel.
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- GCSE Physics (P4) Flashcards on Sparks, created by Rebecca Smith on 08/04/2017.
- Created by
- Rebecca Smith · Apr 2017
- Updated
- Mar 7, 2018
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