Electricity Flashcards
Which way is conventional current?
Positive to negative
What is current?
The flow of charge
What is current in a series circuit?
Same across all components
What is current in a parallel circuit?
Split across each loop
What is voltage in a series circuit?
Shared
What is voltage in a parallel circuit?
Same across all components
What is electrical charge measured in?
Coulombs (C)
Equation to calculate CHARGE?
Q = I * T
(C) (A) (s)
Coulombs = current * time
What is resistance?
When electrons collide with metal ions, the resistance tells us the amount of pd required to drive the current through the wire.
How do you calculate voltage?
V = I * R
(C) (A) (Ω)
Voltage = Current * Resistance
2 Characteristics of a directly proportional graph?
Straight line
Goes through origin
Describe IV graph for filament lamp:
Ohmic Region: At low voltages, the current through the filament lamp is directly proportional to the voltage applied. This region appears as a straight line on the graph.
Transition Region: As the voltage increases, the filament’s resistance increases due to the heating effect. The graph starts to curve upward, indicating a non-linear relationship between current and voltage.
Saturation Region: At higher voltages, the filament reaches its maximum temperature, and the resistance stabilizes. The graph becomes less steep and approaches a plateau.
How does a filament lamp work?
As current flows through the wire, it heats up glowing giving off light.
What does a diode do?
It lets current only flow through in 1 direction.
The rule for resistance in series circuits :
It adds up.
Purpose of an LED?
To light up as current passes through.
The rule for resistance in parallel circuits :
Lower than the lowest one
LDR conditions to work?
Light: Low resistance
Dark: High resistance
What is zero error?
When the equipment should be 0 but is not. Called systemic error.
What is systemic error?
An error that can be reduced by repetition.
Definition of power:
Power is the rate at which energy is transferred.
Equation of power?
(Which includes voltage)
P = E * T
Power = Energy * Time
(W) (J) (s)
What is the benefit of AC current?
Equation of power?
(Which includes resistance)
P = I^2 * R
