Electricity Flashcards
Ammeter
A device used to measure the electric current,connected in series with components
Kirchoffs 1st law
The sum of the currents entering any junction is always equal to the sum of the currents leaving the junction
(A form of conservation of charge)
Conservation of charge
Physical law stating charge is conserved in all interactions; it cannot be created or destroyed
Conservation of energy
Physical law stating that energy cannot be created or destroyed, just transformed from one form into another or transferred from one place to another.
This is the situation in any closed system.
Coulomb
Unit of electric charge C
1c = 1A x 1s
Efficiency
The ratio of useful output energy to total input energy
Electromotive force e.m.f
The electrical energy transferred per unit charge when one form of energy is converted into electrical energy , measured in volts
Internal resistance
r
The resistance of a battery of cell, measured in ohms
Kirchoff’s second law
The sum of the emfs is equal to the sum of the pds in a closed loop ( a form of conservation of energy )
Ohms law
The electric current through a conductor is promotional to the potential difference across it , provided physical conditions, such as temperature, remain constant
Parallel circuit
A type of circuit where the components are connected in two or more branches and therefore provide more than one path for the electric current
Potential difference ,p.d
The electrical energy transferred per unit charge when electrical energy is converted into some other form of energy
Resistance (R)
A property of a component that regulated the electric current through it . Measured in ohms
Resistivity
The ratio of the product is resistance and cross-sectional area of a component and its length
Series circuit
A type of circuit where the components are connected end to end and therefore provide only one path for the electric current
