Electromagnetism Flashcards
What are some characteristics of a circuit diagram?
- The circuit is always rectangular, with straight lines and right angles at junctions
- The power source is at the top of the circuit, being a battery or power supply
- The individual circuit parts are drawn in simplified ways to allow quick understanding of the circuit e.g a bulb is a circle with an x in it, or an ammeter is a circle with an a in it
See Simple Circuits for more information
Check your books or online for all of the symbols, theyre important. Most important ones are DC Power Supply (im 90% sure thats what we use), resistor, variable resistor, bulb, ammeter and voltmeter
Define “In series”
In the context of a circuit
In series means that it is part of the same loop, with Ammeters always being connected in series
Not in Slides, but lesson notes
Define “in parallel”
In the context of a circuit
In parallel means it is on its own loop that splits away from the rest of the circuit at a junction. Voltmeters are always connected in parallel
Not in Slides, but lesson notes
Describe Current (I)?
- Measured in Amps
- Measured using an ammeter (suprisingly)
- The Current is the amount of electric charge moving per second
Slide 7 Simple Circuits
for some reason theres a weird equation to calculate it in my book but I dont think we need it because it has some confusing things like joules and stuff
Describe Voltage (V)?
- Measured in Volts (no way)
- Measured using a voltmeter (who wouldve guessed)
- Also known as potential difference
- The pressure that pushes electrons through a circuit
Slide 8 Simple Circuits
Describe Resistance (R)?
What is its unit and how is it calculated
- Measured in Ohms, which is written as Ω
- Resistance is a measure of the opposition a mnaterial exerts against the flow of electrons
- Measured using the current and voltage passing through it
This formula can be changed to make V or I the subject, but yall prob know how to do that also its called ohms law
V (V)
R (Ω) = ——–
I (A)
Slide 9 Simple Circuits
Define Flux
“The force per (unit of current) per (unit of length)”
Signifies the strength of a magnetic field
Unit is tesla (T) and is equal to 1Nm^-1A^-1
Slide 8 Magnetic Fields
Describe Fleming’s left-hand rule
The direction of the force acting of a wire carrying a current can be predicted using this.
When holding out your left hand in a specific orientation (see slide 6 Magnetic Fields) the thumb indicates motion, the index figer the magnetic field (north to south) and the middle finger indicates current.
Slide 6 Magnetic Fields
State the relationship between force, flux, current, length of wire, and angle between wire and field
Force = Flux * Current * length of wire in field * sin(angle between wire and field)
Or:
F = BILsinθ
Or rearranged:
B = F / ILsinθ
Slide 8 Magnetic Fields
Equation will likely be given if needed
