Fields and their consequences

Describe Fleming’s left-hand rule

1st finger: field

2nd finger: current

Thumb: motion (force)

Describe Fleming’s right-hand rule

Thumb: motion (force)

Fingers: field

State a similarity of gravitational and electrostatic forces

Both have inverse-square force laws that have many characteristics in common.

State a difference of gravitational and electrostatic forces

Masses always attract but charges may attract or repel.

Define an equipotential surface

A surface in an electric field where the electric potential is the same everywhere, meaning if you move a charge along the surface no work is done.

Define escape velocity

The minimum velocity which a body must have in order to escape the gravitational attraction of a particular planet or other object.

Define synchronous orbits

An orbiting object completing an orbit in the same amount of time as the object it’s orbiting completes one rotation.

Define a geostationary orbit

Remains directly above the equator and is in the plane of the equator.

State one use of geostationary orbits

Telecommunications

State one use of low orbits

Weather/ military applications

Define permittivity

The ability of an electric field to pass through

What is the formula for half-life?

0.69RC

Direction of force on charged particles

Towards negative, away from positive

State Faraday’s Law

The induced emf in a conducting circuit is proportional to the rate of change of magnetic flux linkage.

State Lenz’s Law

the induced emf and resulting current will oppose the change in magnetic flux that caused them.

Define magnitude of induced emf

Rate of change of flux linkage

Formula for calculating RMS current

Peak current/ root 2

Describe the production of eddy currents

Change in magnetic field induces electrical currents within the conductor in closed loops.