Topic 3: Electricity Flashcards
Ammeter
A device used to measure electric current
Cell
Provides electrical energy to charges in a circuit
Battery
Provides electrical energy to charges in a circuit
Voltmeter
A device used to measure voltage or potential difference
Variable resistor
Used to vary the size of current in a circuit
Motor
Converts electrical energy to kinetic energy
Switch
Allows current in a circuit when closed. Used to switch on circuits
Bulb
Converts electrical energy to light energy
Resistor
A component that restricts the flow of electrical current
Solar cell
Renewable energy source. Provides electrical energy to recharge batteries
Fuse
Melts to break the circuit if the current is too big
Diode
Allows current to flow through in one direction only
Capacitor
Used in electronic ampilifiers and timing circuits
Light dependant resistor (LDR)
Resistor whose resistance changes with light falling on it
Thermistor
Device where the resistance will change with temperature
Speaker
Converts electrical energy to sound energy
An ammeter is used in…
Series
An voltmeter is used in…
Parallel
As we increase resistance, the current…
Decreases
As we increase voltage, the current
Increases
Electricity
The presence or flow of charged particles
Ohms Law (formula)
V=IR
Voltage (V) unit
Volts (V)
Current (I) unit
Amps (A)
Resistance (R) unit
Ohms (Ω)
More voltage =…
More current
More lamps in a circuit =
Less current but more resistance
Current in series
Current is the SAME at all points
Will a series circuit stop if there is a break?
Yes, current will stop at all points
Relationship formula for series circuit (current)
Is = I1 = I2 = I3
Current in parallel
Current is DIFFERENT at some points. Branches all add up to the supply circuit
What does current do in a parallel circuit?
It splits and rejoins to return to the supply
Will a parallel circuit stop if there is a break?
No, the current can still flow in other branches
Relationship formula for parallel circuit (current)
Is = I1 + I2 + I3
Two equations to calculate power
P = E/t & P = IV
Energy (E) unit
Joules (J)
Time (t) unit
Seconds (s)
Power (P) unit
Watts (W)
What is UK mains voltage?
230V
What does the number of electrons determine?
Current
Voltage in series
Voltage SPLITS and rejoins to the supply circuit
Voltage in parallel
Voltage stays the SAME at all points
Voltage in series relationship formula
Vs = V1 + V2 + V3
Voltage in parallel relationship formula
Vs = V1 = V2 = V3
Potential Energy
Ep, is the energy gained by a mass, m, while rising to a height, h, working against a gravitational force.
Potential Energy formula
Ep = mgh
Energy unit
Joules
Kinetic Energy
Ek, is the energy which an object of mass, m, possesses by being in motion at speed, v.
Kinetic Energy formula
Ek = 1/2 mv²
Work Done
Ew, is the amount of energy it takes to do a task.
Work Done formula
Ew = Fd
What does F also equal in vertical motion?
W=mg
Distance also equals…
height
