Electricity Flashcards
charge (Q)
Can either be positive or negative, tells us how it will be affected in a electric field,
The units of charge
Coulombs (C)
current (I)
The measure of electric charge transferred per unit of time
Units of current
Amperes (A)
potential difference
The measure of energy given to the charge carriers in a circuit
What is potential difference sometimes called
Voltage
Unit of potential difference
Volt (V)
resistance (R)
The measure of opposition to the transfer of current
Unit of resistance
Ohms (Ω)
power (P)
The measure of energy transferred to an electrical component per unit of time
Unit of power
Watts (W)
Energy
Energy is the capacity for an object to do work, it is a concept used to explain why certain things happen
Unit of energy
Joule J
Alternating current
AC is when the transfer of charge rapidly swaps direction
Example of AC supply
Uk mains electricity
Direct current (DC)
DC is when the transfer of charge remains constant in one direction,
Electric field
An electric field is a region in which a charged particle would experience a force.
Charged particle
A charged particle is a particle with a charge, examples of these are positively charged protons and negatively charged electrons
Conductor
A conductor is a material where charge is able to flow
Insulator
A material where charge is not able to flow
Ohms law
Ohms law states that as potential differance across a resister increases the current will also increase V=IR
V=IR
Potential difference = current x resistance
Multi meter
A device used to measure various values of a circuit
Ammeter
A device used to measure the current at a point in the circuit,must be connected in series
Voltmeter
Used to measure the potential difference across a component in the circuit, must be connected in parallel
Cell
A single source of electrical energy, DC power source
Battery
Multiple cells connected in series
Lab pack
A power supply with variable voltage, can either be AC or DC
Resistor
Component used to oppose the transfer of current in a circuit
Diode
A device which will only allow charges to be transferred in one direction
Q= IT
charge(C) = current(A)× time(s)
The rules of series circuits
Current stays the same at all points
Voltage adds up to supply
Resistance adds up to total
Parallel circuit rules
Current adds up to supply
Voltage stays the same at all points
Resistance = 1/RT = 1/R1= 1/R2 = ans Rt= 1/ans
Rules of charge
Opposite charges attract
Like charges repel
What surrounds all charged particles
Electric field
Example of a conductor
Aluminium, steel, gold, copper, silver, graphite
Example of a insulator
Plastic, glass, rubber, wood, air, oil
Fuse ratings
3A for appliances of power less than 720W and 13A for appliances greater than 720W
Resistance in parallel
1/Rt = 1/R1 = 1/R2 ans 1/Rt
V2=(R2/R1+R2)VS
Pd across2 = ( resistance2/ resistance1+ resistance2)*pd across supply
V1/V2= R1/R2
Potential difference1/potential difference2 = resistance1/resistance 2
Rt=R1+R2
Total resistance in series
P =E/T
Power(W) = energy(J)/time(sec)
