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# Help with remembering Phys. Hand formulae! watch

1. Anyone got a good way to remember:

Fleming's Left & Right hand rules - which is for which?

and the one where you have a fist with your thumb up/down.. for magnetic field round a wire... which hand do you use & how to remember it?

any other physics mnemonics very welcome

mine are all extremely laughable so i wont mention them unless asked!

rosie
2. (Original post by crana)
Anyone got a good way to remember:

Fleming's Left & Right hand rules - which is for which?

and the one where you have a fist with your thumb up/down.. for magnetic field round a wire... which hand do you use & how to remember it?

any other physics mnemonics very welcome

mine are all extremely laughable so i wont mention them unless asked!

rosie
THUMB = Motion, (due to a force)

FIRST FINGER = Field

SECOND FINGER = Current

It aint tht good, but tht's how I remember it.
3. (Original post by crana)
Anyone got a good way to remember:

Fleming's Left & Right hand rules - which is for which?

and the one where you have a fist with your thumb up/down.. for magnetic field round a wire... which hand do you use & how to remember it?

any other physics mnemonics very welcome

mine are all extremely laughable so i wont mention them unless asked!

rosie
FLH:- thumb, 1st finger and 2nd finger are all perpendicular to each other.
thuMb= motion (or force)
First finger= field
seCond finger = current
(it's essential to see a diagram, or for someone to show you the finger positioning)

other hand stuff:
right hand can be used to find the direction of magnetic flux arounda current in a straight wire: thumb points towards direction of current, and other fingers curl around the wire,pointing in direction ofthe magnetic field.
similarly, right hand can also be used to find the direction of north in a soleniod depending on the way the current is going around the solenoid (thump points towards north)- again you really must look at pictures cause it's\impossivble to tell you with just text.

a simple mnemonic:
this formula is Very Important to Remember:
V=IR
lol!
4. (Original post by Hoofbeat)
THUMB = Motion, (due to a force)

FIRST FINGER = Field

SECOND FINGER = Current

It aint tht good, but tht's how I remember it.
thats really helpful, thanks (i did know that actually! but forgot)

but any ideas on how you remember which is dynamo/motor... etc?

Rosie
5. (Original post by crana)
thats really helpful, thanks (i did know that actually! but forgot)

but any ideas on how you remember which is dynamo/motor... etc?

Rosie
i dont think we need to know right hand rule (dynamo) for edexcel module 5... left hand rule is MFI, motion(thumb), field(first finger), current(middle finger)... works for me...

there is a right hand grip rule for a wire too... in a thumbs up postition like the icon for this thread... direction of conventional current is the thumb and the fingers go in the direction of the magnetic field...
6. (Original post by S1M)
i dont think we need to know right hand rule (dynamo) for edexcel module 5... left hand rule is MFI, motion(thumb), field(first finger), current(middle finger)... works for me...

there is a right hand grip rule for a wire too... in a thumbs up postition like the icon for this thread... direction of conventional current is the thumb and the fingers go in the direction of the magnetic field...
hmm ok

I know what the rules are n'all.....i just never remember what hand to use

cheers
r
osie

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