magnetism and matter

M

2lm

M for loop

NIA

si unit of m

Am

si unit of M

Am’2 nm t’-1

baxial bar magnet

Mo/4π 2M/r’3

beq bar magnet

Mo/4π M/r’3

torque

M b sintheta

pe

Mb cosethea

diamagnetic

repel strong magnet

perpendicular

go from strong to weak

Mr < 1

X small,-ve

no strong magnet

X no T

paramagnetic

attract strong magnet

parallel

go from weak to strong

Mr>1

X small,+ve

no strong magnet

X 1/T

ferromagnetic

attract weak mahent

parallel

go from weak to strong

Mr>1

X high,+ve

yes strong magnet

X 1/T

mg permeability M

ability of a material to permit mg lines of force

relative permeability Mr

M/Mo

mg force or mg intensity H

degree to which a mf can magnetise a material

H

nI B/M

magnetisation intensity I

M/V. m/a

mg susceptibility Xm

how a easily a material can be mg

Xm

I/H Mr-1

phi

0