Physics Flashcards
What is an electric current
The flow of electrons
Formula for charge
Q =I x t
What is charge (Q) measured in
Columbus
What is current (I) measured in
Amps
What is time (t) measured in
Seconds
Potential difference (voltage)
The driving force that causes charge to flow round a circuit
What is potential difference measured in
Volts
Resistance
The property of any component of a circuit that slows the flow of current
What is resistance measured in
Ohms
Equation for potential difference
V = I x R
Direct current
flows in one direction from positive to negative terminals
Alternating current
Changes direction alternating p.d where the positive and negative ends alternating
Where is AC used
-mains electric supply
-homes
Where is DC used
-phone charger
Series circuit
Where components are connected in line, end to end between the positive and negative terminals of the power supply
Parallel circuits
Where the components are each connected separately to the positive and negative terminals of the power supply
What happens when resistors are connected in series
Total resistance equal to the sum of the individual resistors
Resistors in series
R total = R1 +R2 +Rn
What’s the p.d in parallel circuits
The potential difference is the same across all branches of a parallel circuit
What’s the current in parallel circuits
The current is different in different parts of a parallel circuit
What’s the current in a series circuit
The current is the same in all parts of a series circuit
What’s the p.d in a series circuit
Potential difference is shared between components in a series circuit
Convert 1kV into V
1000V
What’s the frequency of main electricity in uk
50Hz
What’s the main voltage
230v
magnet
a material that produces a magnetic field
magnetism
the force experienced by some types of metals in the earths magnetic field
magnetic field
a region where magnetic materials experience a force
electromagnet
produced when a current flows through a coil of wire
