Physics - Electricity & Static Electricity Flashcards
Forward Biased ?
Reverse Biased ?
Reverse Biased
No current flows
Bulb doesn’t glow
How long will it take this 1kW kettle to use 1 unit of electricity?
1 HOUR
in 1 HOUR a 1kW device will use 1 kWh (one unit) of electricity
kilowatt hour = kWh
Why doesn’t this atom have a charge?
6 positive charges (protons) cancel out the 6 negative charges (electrons)
(+6) + (-6) = 0
How long will it take this 3kW motor to use 1 kWh (1 unit) of electricity?
1/3 of an HOUR
In 1/3 of an hour a 3 kW device will use 1 kWh (one unit) of electricity
kilowatt hour = kWh
Name the wires
Brown LIVE
Blue NEUTRAL
Yellow/Green EARTH
What’s this?
It’s an LDR
Light Dependent Resistor
What’s this?
It’s an LED.
Light Emitting Diode
Current flows only one direction.
It glows when current flows
How many units of electricity will this one kilowatt sandwich maker use in one hour?
1 UNIT
Do you understand this ?
V = IR I = V/R R = V/I
V, Voltage, (volts)
I, Current, (amps)
R, Resistance, (Ohms) Ω
Forward biased ?
Reverse biased ?
Forward biased
Current flows
Bulb glows
What’s this ?
It’s a resistor,
It can control the amount of current flowing in a circuit.
How long will it take this 2kW heater to use 1 unit of electricity?
1/2 HOUR
In a 1/2 HOUR a 2kW device will use 1 kilowatt hour (1 unit) of electricity
How many units of electricity will this 3 1/2 kW motor use in one hour?
3 1/2 UNITS
Two rods of different plastic were charged.
How was this done ?
They were rubbed with a cloth (friction).
How does light affect an LDR?
Bright light ——->low resistance
Dim light ——-> high resistance
What does this symbol represent when we are talking about electricity ?
The unit of resistance, the ohm
Why do you get an electric shock from the shopping trolley only in dry weather?
Moisture in the air allows the electric charges to move and be earthed.
The charges cannot build up.
What does this electrical component do?
It’s a fuse
It protects equipment from current overload
If more than 13 A flows through this fuse it will blow (burn out)
What’s this?
It’s a diode
It allows current to flow only in one direction
What’s this about ?
Voltage (volts) pushes electrons around the circuit.
Current (amps) is the amount of electrons being pushed around the circuit.
Resistance (ohms) makes it hard to push the electrons.
Describe how the force between the two charged rods could be investigated ?
Description
Bring them close together.
Result
They should attract each other, because they are opposite charges.
Describe the relationship between voltage and current shown in the graph
Proportional
The ratio is always the same
