Ex 4) Magnetic field around Solenoid (Electromagnet)
(conductor arranged in a coiled pattern)
A set up like this will form a North and South Pole at each end of
the core.
1. To determine the North and South pole, you
can use a
a)North Pole of a compass
b)2nd Left Hand Rule
Step 1 - Current travels from (-) to (+) terminal,
DRAW the direction of the current on the wires
Step 2 - WITH YOUR PALMS POINTED AWAY, point the fingertips
of your left hand in direction of current flow
Step 3 - thumb - North Pole!!
North Pole on the RIGHT or LEFT???
Right
North Pole - Top or Bottom
North Pole - Right or Left?
2nd Left hand Rule Animation - St. Mary's H.S.
The strength of a magnetic field in a solenoid can be increased by:
1) Increasing or decreasing the number of turns? (of wire)
2) Increasing or decreasing current?
3) inserting a highly permeable core (increases
flux density)
high permeable cores
- Iron, Cobalt,
Nickel
These materials tighten existing flux lines, do not increase # of flux lines
low permeable cores
-air (Pulling out the core)
Applications