Sci. y2 Phy.1 (electricity & magnatism)

• positive(+) repels positive(+), negative(-) repels negative(-), positive(+) attracts negative(-)
• an atom constists of protons(+), electrons(-) and neutrons
• a current is the charge flowing per second
• a battery doesn't produce energie, it only pushes electrons around, electrons are already in the wire
• potential difference is the push to make electrons move
• current is measured in amps, using an ammeter. The symbol for current is I
• potential difference is measured in volts, using a voltmeter. The symbol for potential difference is V
• there are 2 types of electrical circuits. parrallel and series
• a series circuit has 1 loop. if a component stops working, all components stop working as well
• a parallel circuit has several loops. if a component breaks, all components in that loop stop working. all other loops keep working
• in a series circuit the current is the same everywhere and the voltage is the total sum of voltage in every components
• in a parallel circuit the current is the total sum of current in all components and the voltage is the same in every component
• resistance tells you how easy/difficult electrons pass trough componants
• resistance is measured in ohms. the symbol is R
• potential difference / resistance = current
• resistance x current = potential difference
• current x potential difference = resitstance
• a magnet has a north(+) and south(-) pole
• in a electric field there is a force on a charge
• in a magnetic field there is a force on a magnet
• you can find out the shape of a magnetic field using compasses or iron filings
• a wire with an electric current flowing true it has a magnetic field
• if you make a coil and turn on the current you have made a electromagnet
• there are 3 ways to improve the strength of an electromagnet: increase the current, add more loops, add an iron core