A student investigated how the resistance of a piece of nichrome wire varies with length. Describe how the student would obtain the data needed for the investigation.
the answer should include a risk assessment for one hazard in the investigation.

1) The length of the wire needs to be measured and varied (this is order to get a complete set of results for your experiment )2) Then go through each length of wire and measure the current and potential difference for each wire. (in order to calculate resistance later )3) repeat multiple times for each length of wire in order to create an average = sum/n (if need be explain difference between accuracy and precision).4)calculate resistance using equation resistance * current = Voltage for each length of wire

Hazards: Electric shock due to current , overheating wire can overheat , can be minimised by using low currents.

double the distance = divide strength by 4

the minimum amperage that the current in this wire would have to have so that its weight is completely supported by the magnetic force due to earth's field, assuming that no other forces except gravity act on it