Electricity Flashcards
What is electricity?
The flow of electric charge/charged particles.
What is the unit for current?
Ampere, Amp (A); I in equations
What is the unit for charge?
Coulomb (C); Q in equations
What is the unit for energy?
Joule (J); E in equations
What is the unit for resistance?
Ohm (Ω); R in equations
What is the main unit for time?
Second (s); t in equations
What is the unit for potential difference?
Volt (V); V in equations
What is the unit of power?
Yes 💀 (Burke reference)
Watt (W); P in equations
What is the equation that links power, current and voltage?
P = I x V (PIV)
power = current x voltage
What is the equation that links energy transferred, potential difference, current and time?
E = V x I x t (EVIT)
energy transferred = voltage x current x time
What type of electricity do mains supply?
A.C (alternating current)
What type of electricity do batteries supply?
D.C (direct current)
What is the difference between D.C and A.C current?
In D.C, the voltage is always constant, and the electricity flows in a certain direction. In A.C, the voltage changes from positive to negative and from negative to positive, and so does the direction of the current
What is the relationship between light and resistance in an LDR (light-dependent resistor)?
As light increases, the resistance decreases.
What is the relationship between temperature and resistance in a thermistor?
As temperature increases, the resistance decreases.
What happens to current as you increase the resistance in a circuit?
As the resistance increases, the current decreases, provided all other factors are kept constant.
How do you use lamps and LEDs to find out the presence of current in a circuit?
If it lights up, there must be a current in the circuit. If it doesn’t emit light, there isn’t any current.
What is current?
The rate of flow of charge.
What is the relationship between potential difference, current and resistance.
V = I x R (VIR)
potential different = current x resistance
What is the relationship between charge, current and time?
Q = I x t (QIT)
charge = current x time
What is current in solid metal conductors?
A flow of negatively charged electrons.
What happens to current in a parallel circuit?
The current is shared between each component connected in parallel. The total amount of current flowing into the junction, or split, is equal to the total current flowing out.
What happens to voltage in a parallel circuit?
The voltage across each of the components is the same.
What is voltage?
The energy transferred per unit charge passed
