3 Flashcards
Describe what an electric field is.
A place where a charge experiences a force.
Describe what an electric field usually does to charged particles.
An electric field is usually used to accelerate charged particles.
State the meaning of the term ‘electric field strength’.
The force per unit positive charge.
Describe the direction the arrows point in electric field diagrams.
The direction a positive charge would follow.
Describe the electric field strength around a hollow sphere.
Zero inside the sphere and decreasing at 1/r2
.
State the meaning of the term ‘electrostatic potential’.
The work done to bring a positive test charge from infinity to a point in an electric field.
Describe the electrostatic potential around a hollow sphere.
Maximum inside the sphere and decreasing at 1/r.
State the two forces which balance each other in Millikan’s oil drop experiment.
Electrostatic force upwards balanced by weight downwards.
Describe what a magnetic field is.
A place where a moving charge experiences a force.
Describe what a magnetic field usually does to charged particles.
A magnetic field is usually used to deflect charged particles.
Describe what a ferromagnetic material is.
Ferromagnetic materials can be made into magnets. A magnet is held near them and the
dipoles in the materials line up in the same direction.
State the names of three ferromagnetic materials.
Cobalt, Nickel and Iron
Describe the direction of the force between two current carrying wires.
If the current is in the same direction the force is attractive. If the current is in opposite
direction the force is repulsive.
Describe the motion of a charged particle travelling parallel to a magnetic field.
The charged particle will travel at a constant velocity.
Describe the motion of a charged particle travelling perpendicular to a magnetic field.
The charged particle will travel in a circle with the magnetic field providing the central force.
