Electrical Quantities Flashcards
How do Charges Interact?
Like Charges Repel one another while Opposite Charges attract.
What is an electric field?
Similar to magnetic fields an electric field is a region in which an electric charge experiences a force.
What is Electric Current?
Current is the amount of charge passing through a point per a unit of time
I = Q / t
What is electric Charger?
Charge is measured in coulombs.
Convectional Current vs. Flow of Electrons
Positive → Negative vs. Negative → Positive
How can electrical current be measured?
An ammeter can be used to measure the magnitude and direction of the current.
- ensure the range is correct!
What is Electromotive force? (e.m.f)
It is the electrical work done by a source in moving a unit charge around a complete circuit.
E(V) = Wd / Q
Work done per unit charge is also called potential difference!
How are Volts measured?
By using a voltmeter, connect positive to positive; negative yo negative, connected in parallel
What is Resistance?
Resistance is how difficult current travels through a conductor.
V = IR
or
R = V / I (ohms)
How is resistance measured?
Resistance can be measured by:
- setting up a circuit diagram with ammeters, voltmeters and a resisor.
How do cross-sections of a wire affect resistance? Also, how does length affect resistance?
A larger cross section has less resistance, whilst a smaller one has more. Resistanceis inversely proportional to the crossection
Longer wires have larger resistance, shorter ones have less. Resistance is directly proportional to length.
How does Power relate to electricity?
P = I x V
E = Pt
T = I x V x T
