Magnetism and Electromagnetism Questions

• When the south poles of two bar magnets are brought close together, there will be a force of attraction.
• The operation of an electrical generator relies on electromagnetic induction.
• Magnetic flux flows from the north pole to the south pole within the magnet.
• A voltage is induced across a conductor if it remains absolutely stationary within a magnetic field.
• The induced emf of a conductor cutting flux lines is directly proportional to the rate of cutting.
• The magnetic field, current through the Hall element, and Hall voltage are all at right angles to each other.
• A magnetic material such as iron can change the course of magnetic lines of force.
• The unit of magnetic flux density is the weber.
• The Hall voltage is the voltage created by a conductor moving through a magnetic field.
• The ability of a material to maintain a magnetized state (without the presence of a magnetizing force) is called retentivity.
• A magnetic field is produced around a current-carrying conductor.
• Ferromagnetic materials have pre-existing magnetic fields.
• The induced voltage across a stationary conductor in a stationary magnetic field ___.
• After the magnetizing force has been removed, the ratio of the remaining magnetic flux to the saturated magnetic flux is called _____________.
• The movable part in a relay is the _____.
• A group of force lines going from the north pole to the south pole of a magnet is called the magnetic ___.
• The ___ is an electromagnetic device that contains a coil rotating on a jeweled bearing mount.
• When the speed at which a conductor is moved through a magnetic field is increased, the induced voltage will _____.
• ___ is the ability of a material to remain magnetized after removal of the magnetizing force.
• When the current through a coil reverses direction, the magnetic field around the coil _____.