U2 Definitions Flashcards
Field of force
Region of space within which objects with a particular property experience a force
Gravitational field
Region of space within which a mass will experience a force
Electric field
Region of space within which a charge will experience a force
Magnetic field
Region of space in which a moving charge will experience a force
Gravitational field strength
g = force experienced per unit mass in N/kg
Newtons law of universal gravitation
Between any 2 point masses there exists an attractive force which is directly proportional to the product of the masses, and inversely proportional to the square of their separation
Keplers 3rd law
Square of period of revolution is directly proportional to cube of their mean distances r, from it
Electrical field strength
E field strength at a point is the force experienced per unit positive charge at that point
Coulomb’s law
Between every 2 point charges there is an electrical force which is directly proportional to the charge of each and inversely proportional to the square of their separation
Capacitance
The charge stored per unit volt
Farad
One farad is the capacitance that stores 1C of charge across a pd of 1V
Time constant
Time taken for the pd or Q or I to fall to 1/e of its initial value while a capacitor discharges
Magnetic flux density, B
The force per unit current carrying length
Tesla
1 T is the magnetic flux density which will cause a 1m long conductor carrying 1A at right angles to the field to experience 1N force
Faraday’s law
Induced emf is directly proportional to the rate of change of flux linkage
