magnetic poles always come in pairs (T or F)
T
What is the SI unit for magnetic field?
tesla (T)
Magnetic field are always straight lines (T or F)
no closed loops
In which way does the the dipole field point?
From North to South
Uniform magnetic field can happen when....
the Pole faces are larger than the area space between them
When does a charged particle not experience a magnetic force?
when it is moving parallel to the field
The force is _________ to both the velocity and the field
perpendicular
The force on a negative charge is in the __________direction
opposite
If the velocity of a charged particle is ___________ to the field there is no magnetic force and the particle moves in a straight line.
parallel
If the particle is moving perpendicular to a uniform magnetic field, its path will be a ____________.
circle
If the velocity has both perpendicular and parallel components, the particle moves in a___________
helix
A current carrying wire in a magnetic field experiences a magnetic force unless the current is ___________to the field.
parralel
If the magnet is not moving then the field is
constant
When is the magnetif flux 0?
when the plane of the loop is parallel to the field.
When is the magnetic flux at it's max?
when the plane of the loop is perpendicular to the field
if light strikes a metal, electrons are emitted.
photoelectric effect
In the photoelectric effect, The kinetic energy of the electrons increases ________ with frequency.
linearly
is one in which the direction of the current does not change. Usually the magnitude of the current is constant.
Dc current
the direction periodically reverses. Usually the current is sinusoidal.
AC current
The current and voltage are in phase, meaning their peaks occur at the same time.
AC current
n an ideal transformer the flux through the secondary is ____________ the flux through the primary.
the same as
Outlets, lights, etc. in a household circuit are wired in _________. One side of an outlet is neutral and connected to ground, the other side is hot.
parallel
negatively charged particle is moving in a uniform magnetic field which is perpendicular to the particle's velocity. What happens to the particle's kinetic energy
negatively charged particle is moving in a uniform magnetic field which is perpendicular to the particle's velocity.
A coil of wire is attached to a galvanometer. A second coil is connected through a switch to a dc power supply. In which of the following cases was a current induced in the coil so that the galvanometer needle deflected?
A. When the switch is first closed
Both A and B
A flexible coil of wire is attached to a galvanometer. The coil is placed between the poles of a strong magnet. In which of the following cases was a current induced in the coil so that the galvanometer needle deflected?
A. Flatten the coil so that its ar
E. All of the above.
In the absence of an external magnetic field their magnetism cancels out.
An external field distorts the orbits causing the atoms to produce a magnetic field in the opposite direction of the external field.
Diamagnetism
An atom or molecule with one or more unpaired electrons acts like a tiny magnet due to the spin and orbital motion of its electrons. Such materials are
paramagnetic
those that can become strongly magnetized, such as iron and nickel.
ferromagnetic
A compass in a magnetic field will line up __________.
with the north pole pointing in the direction of the magnetic field
With the wire back at its initial location, you connect a second identical battery in series with the first one. When you close the switch, how does the new angle of deflection of the north pole of the compass needle compare to its initial deflection?
It is larger
A loop of wire carries a current. The resulting magnetic field __________.
is similar to that of a bar magnet perpendicular to the plane of the loop
A metallic conductor moving at a constant speed in a magnetic field may develop a voltage across it. This is an
motional emf