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Q1: Can ions in water produce magnetic field:
Moving charged particles produce magnetic field while moving. Since ions are charged particles, they
would produce magnetic field only when they are moving.
Q2: How do we measure magnetic field?
Guass meters are used to measure magnetic field. Guass meters use the principle of Hall effect.
The Hall effect is the production of a voltage difference (the Hall voltage) across an electrical conductor,
transverse to an electric current in the conductor and a magnetic field perpendicular to the current.
The hall voltage is directly proportional to the magnitude of magnetic field according to following
expression. Therefore, stronger the magnetic field, stronger will be the Hall voltage. Voltage can be
measured through Voltmeters.
I=current across plate length
B=magnetic flux density
d=depth of plate
n=charge carrier density of carrier electrons (numer of charge carriers per volume)
e=electron charge
Q3: Do magnetic field lines exist inside a magnet or solenoid? If yes, in what direction?
Yes, magnetic field lines exist in both magnets and current carrying solenoid. Magnetic field lines exit a
magnet near its north pole and enter near its south pole, but inside the magnet B-field lines continue
through the magnet from the south pole back to the north.
Q4: Does the magnetic field inside the solenoid depend upon the radius of the solenoid?
The magnetic field inside the solenoid in class discussions is to be uniform inside the solenoid.
Therefore this uniform field does not depend on the radius of the solenoid.
However, the magnetic energy enclosed by the volume of the solenoid will vary with radius.