TOPIC 8:ELECTRIC AND MAGNETIC FIELDS

What is the equation for gravitational field strength ?

g=GM/R^2

What is the equation for Electric field strength(3)

KQ/r^2
E = F/q
E=V/D

What is the equation for Electrostatic force

Fe=KQQ/r^2

What is the equation for Gravitational force

Fg=GMM/r^2

What is a Field

A field is an area of space that has an influence (force) on something

What is the graphical relationship/ representation of gravitational field strength

inverse square graph as gravity is inversely proportional to the r^2

What is flux density

The strength of a magnetic field.

what is an electric field

A region of space in which charged particles experience either an attractive or repulsive force depending on the charge of the particle and direction of the field

What is a magnetic field

A region of space in which magnetic materials and moving electric charges feel a force.

What does a positive symbol signal in an electric field

Repulsion

what does a negative symbol signal in a electric field

Attraction

Explain Fleming left hand rule

The relative direction of motion(force), field direction and current direction in the motor effect.

Explain the magic wand experiment in relation to

Electric Fields

Coulomb's Law

The size of the force that acts between two point charges is proportional to the product of their charges and inversely proportional to the square of their separation

Define capacitance

The ratio of the charge stored in a capacitor to the potential difference between the two sides of the capacitor.

Why is the symbol for gravitational Force always negative

It is always negative because it is an Attractive force

Explain Columb's Law for Attractive and repulsive forces mathematically

opposite charges
+ & - = -
-=attraction
opposites charges attract

Like charges
- & - =+
+ & + = +
+= repulsion
like charges repel

What are Electric Field Lines

A way of representing an electric field in a diagram

In What direction do electric field lines point.

They point in the direction that a positive charge would experience a force, point positive to negative.

What is Electric Potential.

Defined at a point. The work done moving a unit positive charge from an infinite distance away to that point.

What is Electric Potential Difference

The work done per unit positive charge in moving between two points

What is the equation for Electric Potential

V = kQ/r

Why is KQ/r^2 not the generic equation for eletric field strength

it only applies to eletric field strength at a distance of r from Q

What is the equation for the electric field strength acting between two plates

E=V/D

Explain the semolina experiment in terms of electric fields

The potential difference generated between the two plates creates an electric field which creates a force that acts on the charge of the semolina powder causing them to accelerate back and forth between the plates as they pick up and lose charge.