3 WAYS TO INCREASE THE STRENGTH OF AN ELECTROMAGNET
* INCREASE NUMBER OF COILS THAT WRAP AROUND THE CORE
* INCREASE THE CURRENT FLOWING THROUGH THE COIL
* CHANGE THE CORE MATERIAL TO BEST SUIT THE ELECTROMAGNET

fluxlines

Magnetic flux (Greek letter Φ (phi)), is a measure of the magnetic field strength existing on a two dimensional surface, such as one side of a magnet.

1. cant cross
2. try to shorten
3. north to south
4. cant be broken

exam

4 things i found hard i found everything hard in the exam

redraw R3, R4, R5 to make one resistor in a parallel circuit with R2, then add the inverse of R2 with the inverse of R3+R4+R5 the inverse the answer then you should now have 3 resisters in series then add them together to give you the total resistance. now if you use ohms law I=V/R you can work out the current through the circuit at each resistor an also the voltage across each resistor.

Total voltage is the same as the supply voltage on every branch of the circuit.
Total Resistance = 1/R1 + 1/R2 = 1/RT
Current breaks of down the branches of the circuit then rejoins to the supply current.

series circuit

Total Resistance is the all the resistance added together. R1+R2=R3

Total Voltage adds up to the supply voltage
Total current stays the same thought out the hole circuit.

resistor colour code

the colour code table matches up with the bands on the resistor and that is how you find out what type it is