Electromagnetism Flashcards
What does Coulomb’s law state?
The force between the charges is directly proportional to the magnitude of each charge and inversely proportional to the square of the distance.
Define electric field strength.
The force per unit positive charge.
Define electrical potential.
The work done in moving 1 coulomb of positive charge from infinity to that point.
What is an electronvolt (eV)?
The energy acquired when one electron accelerates through a potential difference of one volt.
What can a wire be coiled into to produce a stronger magnetic field?
A solenoid
Describe Milikan’s oil dtop experiment.
Milikan sprayed charged oil droplets into an electric field between two parallel plates.
By varying the potential difference across plates, he was able to suspend the droplet by balancing the weight down-wards with the upwards electrostatic force.
The mass of the droplet could be calculated by measuring its terminal velocity.
This allowed the charge on the droplet to be calculated.
Milikan concluded that the values of electric chatge were integral multiples of 1.6x10-19 C.
What are the four fundamental forces of nature?
Gravitational
Electromagnetic
Strong
Weak
What fundamental forces act within an atom?
Strong force
Weak force
What is strong force?
It is responsible for holding the nucleus of an atom together.
What is weak force?
Responsible for the decay of a neutron into a proton, electron and anti neutrino.
What two fundamental forces have an infinite range?
Gravitational
Electromagnetic
What is gravitational force?
Attractive force between particles with mass.
What is electromagnetic force?
It affects particles that have an electric charge.
Describe the magnetic induction around a current-carrying wire.
The magnetic induction (B) at a distance (r) from the conductor is directly proportional to the current (I) and inversely proportional to the perpendicular distance (r).
