Definitions Flashcards
Potential difference
The work done per unit positive charge
Current
The rate of flow of charge
Ohm’s law
Current through a conductor is directly proportional to the potential difference across the conductor at constant temperature
Resistance
A materials opposition to the flow of electric current
EMF
Total energy supplied per coulomb of charge by the cell
Magnetic flux density (B)
A representation of the magnitude and direction of the magnetic field
Magnetic flux linkage
The product of the number of turns on the coil and the flux through the coil
Faradays law
The emf induced is directly proportional to the rate of change of magnetic flux (flux linkage)
Lens’s law
The induced current flows in a direction so as to set up a magnetic field to oppose a change in magnetic flux
Resultant vector
The single vector that has the same effect as all the original vectors acting together
Distance
The length of path travelled
Displacement
A change in position
Speed
The rate of change of distance
Velocity
The rate of change of displacement
Acceleration
The rate of change in velocity
Weight
The gravitational force the earth exerts on any object on or near its surface
Normal force
The perpendicular force exerted by a surface on any object in contact with it
Frictional force
The force that opposes the motion of the object and acts parallel to the surface with which the object is in contact
Newton’s first law
An object continues in a state of rest or uniform velocity unless it is acted upon by a net or resultant force
Newton’s second law
When a net force, Fnet, is applied to an object of mass, m, it accelerates in the direction of the net force. The acceleration, a, is directly proportional to the net force and inversely proportional to the mass
Newton’s third law
When object A exerts a force on object B, object B simultaneously exerts an oppositely directed force of equal magnitude on object A
Newton’s law of universal gravitation
Every particle with mass in the universe attracts every other particle with a force which is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centres
Gravitational field
The force acting per unit mass
Coulomb’s law
Two point charges in free space or air exert forces on each other. The force is directly proportional to the product of the charges and inversely proportional to the square of the distance between them
Electric field
A region of space in which an electric charge experiences a force. The direction of the electric field at a point is the direction that a positive charge would move if placed at that point
The magnitude of the electric field at a point
Force per unit positive charge. E = F/q where E and F are vectors
Vector
Physical quantity that has both magnitude and direction
Scalar
Physical quantity that has magnitude only
Inertia
Property of an object that causes it to resist a change in its state of rest or uniform motion
Power
Rate at which work is done
Gravitational field and acceleration due to gravity
ARE EQUIVALENT!!!!!!
