Question

Briefly describe a measurement you can do using a compass to determine information on the direction and/or strength of the magnetic field passing through the wire in Oersted’s experiment. Include your prediction on how you expect the compass reading to vary as you change one parameter (e.g. distance or current through the wire).

Being critical of your measurement described in the previous question, what errors or complications could arise that would prevent you from obtaining conclusive results? Include a precaution or extra steps that could be undertaken to ensure conclusive results. (One optional choice here is how to deal with background signals produced by Earth’s magnetic field).

Answer 1

The oersted experiment is based upon the ampere's swimming rule

This states that assuming a swimmer swimming along the direction of the current , then magnetic north of the compass will deflect towards the left hand side of the swimmer and vice versa

Recording the compass deflection for different current values

we would have to change the wire current for different values and have to note the deflection produced by the compass

we would find that more the current more the deflection hence stronger the magnetic field

Recording the compass deflection for different position for same current value

we would have to change the position of the compass and have to note the deflection produced by the compass

we would find that more the distance from the wire ,  lesser the deflection hence weaker the magnetic field

Hence magnetic field directly proportional to the current and inversely proportional to the distance.\

Errors and Precautions

There are various factors that arises errors

• the deflection is the net result of earths magnetic field and field induced by wire
• the power supply must be used to get constant current supply
• the distance between the wire and compass centre must be measured perpendicular to the wire