Which Fleming's Hand Rule to Use?

🔴SCENARIO 1:

A wire XY placed on a weighing balance that has magnetic field on it.
Q. which fleming's hand rule should we use to find the direction of current in the wire?

🔴SCENARIO 2:

A rectangular coil of wire placed on a magnetic field. Current is passing through the wire.
Q. which fleming's hand rule should we use to find the direction of force in the side SP?

🔴SCENARIO 3:

Q. which fleming's hand rule should we use to find the force on the wire?

(edited 11 months ago)

Reply 1

Aleksander Krol

i used FLH rule for SCENARIO 1 and i got the direction of current pointing in the Y to X direction. but the ms says X to Y. how?? the direction of force is downwards, magnetic field direction going from North to South, giving me at the end Y to X as the direction of current in the wire :/

Reply 2

Joinedup

I don't understand the first diagram - if the current is going parallel to the x axis and the B field is going parallel to the y axis then the force would be parallel to the z axis
i.e. into or out of the page... but the weight is acting downwards?

for the second you don't even need a hand rule.
there is only a force on the parts of the coil that are crossing the magnetic field lines so A is correct and the question is only looking for one correct row. (but if you did it'd be the Left Hand Rule)

third - left hand rule again... its the rule for situations where you're looking at the force produced on a current carrying conductor in a magnetic field.

https://www.bbc.co.uk/bitesize/guides/z8kvtv4/revision/2