How is each piece when a bar magnet is broken in two?
as magnetic as the original magnet
actually stronger than the original magnet
half as strong as the original magnet
no longer magnetic.
Where does the term magnetism come from?
the interaction of relativistic electric fields on moving charges
from a region of Magnesia, a province of Italy
from a region of Magnesia, a province of Greece
the Latin term for “attraction of metal”
Calculate the value of magnetic induction at a distance 0.9m on the axial line of a short magnet of length 7cm and pole strength 3 × 10-3 A-m.
7.8 × 10-11Web/m2
5.2 × 10-11Web/m2
6.3 × 10-10Web/m2
9. 3 × 10-10Web/m2
When a bar magnet is thrust into a coil of copper wire, the coil tends to
repel the magnet as it enters
attract the magnet as it enters
both of these
neither of these
When does an iron rod become magnetic?
positive ions accumulate at one end and negative ions at the other end.
its atoms are aligned having plus charges on one side and negative charges on the other.
the net spins of its electrons are in the same direction.
its electrons stop moving and point in the same direction.
What is the main difference between electric charges and magnetic poles?
electric charges can be isolated, magnetic poles cannot be isolated
electric charges cannot be isolated, magnetic poles can be isolated
electric charges both attract and repel, magnetic poles only attract
electric charges both attract and repel, magnetic poles only repel
When looking at iron filings that have been allowed to interact with a magnetic field, what does the density of lines suggest?
that the magnetic field is weakest there
that the magnetic field is strongest there
that the electric field is un-canceled there
that the electric field is the strongest there
Which is not a material that is commonly used to make a magnet?
iron
cobalt
nickel
copper
The ability of a material to remain magnetized after removal of the magnetizing force is known as
permeability
reluctance
hysteresis
retentivity
What does a moving charged particle experience if it moves through a static magnetic field?
an acceleration in the current direction
a deflection that is parallel to the magnetic field
a deflection that is perpendicular to the current and parallel to the magnetic field
a deflection that is perpendicular to both the magnetic field and the current
