3.3 Flashcards
What is voltage
Is a measure of thr difference in electrical charge between 2 points
What is v
Voltage and it is the number of joules of energy per coulomb of charge
What is emf
Electromotive force is equal to the terminal potential difference when no current flows
What is PD
It is a potential difference which measures the different potential (voltage) between 2 or more points in a circuit
What is the unit for V, emf and PD
VOLTS (V)
What is voltage also represented
E
V = E/Q
Where E is in Joules (J) and Q is a charge in coloumbs (C)
Voltage unit is J/C
What are 2 kinds of electric voltage
Direct current (DC)
Alternating current (AC)
If a voltage maintains same polarity over time what is it called
DC Voltage
If voltages magnitude and polarity changes what is it called
AC voltage
What are the 2 words used when discussing the potential difference
‘Across’ a component or
‘Between’ 2 named points
What is the symbol for ‘I’ and the equation
I = Q / t
‘I’ is the ampere (A) in current
Q is the amount of charge in coulomb ( C)
And t is the time taken in seconds
Equation for resistance
R = V/I
Resistance in ohms
V is the voltage in volts
I is the current in ampere A
What is a resistance
It is the opposition to the flow of electric current and is a measure of how much energy is required to cause a current to flow
What is conductance
It’s to do with electrical resistance indicates to which an electrical current is restricted. Higher the resistance tye more current is restricted
