Electric Power Clarification

[Nephix]

Hi there ^^

I was just wondering if anyone could help me clear up some electric power shiz,

I'm struggling to understand the direction of induced currents/fields/forces in solenoids

First off: VCAA 2010 Exam 2 Question1.

How do you work out the direction of the magnetic field, because I thought that it went from North to South and you could use the right hand grip rule (fingers current, thumb field) and work out the North end. But I always seem to get the opposite direction...

Also... with the questions that have two solenoid circuits next to each other (1 with a battery 1 without), how does a current get induced in the circuit without the battery if like a switch is closed or something, like I know the magnetic flux causes an induced current, but how do you apply Lenz's law to it, blah blah blah...

sorry if my questions are pretty vague. anyways happy physics!

[Robert123]

Your first question, I just play it safe and use the RH grip rule, once you followed the first coil you can tell which way the field will go

[Nephix]

Your first question, I just play it safe and use the RH grip rule, once you followed the first coil you can tell which way the field will go

Yeah but with the right hand grip rule, the thumb points in the direction of the field right, so considering that fields go north to south it should be pointing in the south direction?

But nope, it's pointing in the North

[Robert123]

Yeah but with the right hand grip rule, the thumb points in the direction of the field right, so considering that fields go north to south it should be pointing in the south direction?

But nope, it's pointing in the North

I'm no expert on the RH solenoid rule but I believe the thumb points in the direction of the north pole, not the direction of the field

http://etc.usf.edu/clipart/35600/35671/rhrsole_35671.htm

[Nephix]

I'm no expert on the RH solenoid rule but I believe the thumb points in the direction of the north pole, not the direction of the field

http://etc.usf.edu/clipart/35600/35671/rhrsole_35671.htm

Which makes sense, ill see how I go with any future problems, thanks man, appreciate it