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Science P2 Topic 1
Edexcel GCSE additional science physics: static and current electricity
|Describe the structure of an atom
|Protons and neutrons in the nucleus, electrons orbiting the nucleus in shells
|How can an object become electrostatically charged?
|When two different insulating materials are rubbed together, riction causes electrons to be transferred from one material to the other- the two materials become electrostatically charged
|Why must objects be insulators to build up an electrostatic charge?
|So that the charge isn't conducted away
|What is induction?
|Induction is when an electrostatically charged object is put next to a neutral object, repelling or attracting the electrons in this material so that it is more negatively charged on one side
|What are some examples of the dangers of static electricity?
|1) shocks from everyday objects e.g. walking along a carpet then touching a metal door handle 2) lightning is caused by a large spark forming between the clouds and ground 3)fuel rubbing against pipe produces sparks that could ignite fuel fumes
|Give an example of induction
|* A charged balloon sticking to a wall * A charged comb picking up small pieces of paper
|How can the issue of petrol fumes igniting be avoided?
|Use a bonding line to earth the charge
|What is earthing?
|Earthing is the process whereby electrons flow in a direction dependent on their charge to remove excess charge
|What are some uses of electrostatic charge?
|1) Insecticide sprays 2) electrostatic paint spraying 3) finger printers 4) photocopiers
|What is electric current?
|The rate of flow of charged particles
|What is a current in a metal?
|the flow of delocalised electrons
|What is the difference between alternating and direct current?
|Direct: current flows in only one direction (supplied by cells) Alternating: current changes direction many times a second (supplies by generators)
|How is the size of the current measured?
|Using an ammeter, placed in series
|Why can the ammeter be put in series?
|Because current is the same everywhere in the circuit and is conserved at junctions