Electricity, electrostatics and ciruits

• • opposite charges attract and like charges repel

  electric charges act with repulsive electric force on another like charge.

  like = the same

  repulsive electric force = a pushing force

  electric charges act with an attractive electric force on another opposite charge

  attractive electric force = a pulling force
• • neutrons and protons are found in the nucleus
  • electrons > negative
  • Protons > positive
  • neutrons > neutral
  • when they’re more electrons on the outer shell the charge becomes positive. If they are not enough electrons on the outer shell the charge becomes negative.
  • uncharged + charged attact
  • example; when a polytene rod is rubbed by a duster electrons are scratched away from the dusters outer shell and stay on the rod

  
• the greater the distance between two objects the weaker the force acting between them.
• Conductors:

  inside a conductor the electric charge is free to flow, for example; metals. This is why we use wires made of copper
• Insulators: inside an insulator the electric charge cannot move and is stuck in one place.
• when electrons are lost the charge is positive
• When electrons are gained the charge is negative
• For thunder to occur the heat around the environment increases causing the gas particles to move more quicker. As the particles increase in speed the chance of them colliding is higher, and once they collide it causes a sound known as thumder to be produced.
• Objects can have induced charges if they’re uncharged and a charge object is near them
• When static electricity builds up it can cause a spark sometimes resulting in explosions or fires
• Insecticides and sprays:

  • when sprayed the particles move away from each other because they are all the same charge
• Charge us a fundamental property that comes in two types, positive and negative carried by electrons (-) and protons (+)
• Charge is measured in coulombs (c/s) but has its own particular name The Ampère, amp or A
• Current in the rate of flow of charge
• A series circuit has only one pathway for the current to follow so there is no split in the current
• • Charge = Amps (A) multiplied by time (s)
  • Current = charge (q) divided by time (s)

  Remember CAS is QIS
• Two things needed for a current to flow is

  • a complete path
  • energy source
• energy in a battery is stores as a chemical
• Voltage is electrical pressure measured in volts (v) using a voltmeter
• Power is the amount of energy transferred per second measured in watts (W)
• Resistance is how much an object resists the flow of electricity through it measured in ohms (Ω)
• WVA:

  • watts = voltAge multiplied by amps
• resistance formula:

  Ω (ohms) = volts divided by amps
• When two or more cells are connected together this is known as a batter.
• The cells stores chemical energy and transfers it to electrical energy when a circuit is connected
• In parallel circuits components are joined side by side so that there are multiple paths for the current to follow
• In a series circuit all components are joined end-to-end so that current flows through them one at a time
• Current flows from the negative terminal to the positive terminal, of a cell.
• In a series circuit current is the same throughout while voltage is shared between components.
• In a parallel circuit current is shared while voltage is the same in all parts of the circuit