Term 1 Flashcards
Why are the pins made up of Brass?
Brass is a good conductor and it doesn’t rust
What are the 3 types of wires?
Earth wire
Neutral wire
Live wire
What colour is the Earth wire?
Green and yellow
What colour is the Neutral wire?
Blue
What colour is the Live wire?
Brown
How to calculate the power?
Power(Watt)= energy transferred(joules)
——————————————
time(seconds)
How to calculate resistance?
Power=Current x Resistance
How to calculate charge?
Charge flow=current x time
What happens when charge flows through a resistor?
When charge flows through a resistor, energy transferred to a resistor makes it hot
How to calculate Efficiency?
Efficiency=its output power
———————— (x100)
its input power
What do Fuse do?
If to much current passes through the wire in the fuse, it melts and cuts the live wire off
What is the Power Grid?
How electricity gets to peoples homes
What is a direct current?
A current that only flows in 1 direction
What is an alternating current?
A current that can move in both directions
What is the frequency of an alternating current?
50hz, which means that can change direction 50 times per second
What is a Oscilloscope?
A device used to display the shape of an electrical wave
What is a three pin plug?
Has a live pin, a neutral pin and an earth pin
What is a Step up transformers?
electrical device used to step-up the size of an alternating potential difference
What is a Step down transformers?
electrical device used to step-down the size of an alternating potential difference
What is a plug?
a plug has an insulates case and is used to connect the cable from an appliance to a socket
What is an earth wire?
the wire in a mains cable used to connect the metal case of an appliance to earth
What is the power measured in?
Watts (W)
What is the energy measured in?
Joules (J)
What is the time measured in?
Seconds
Explain when a toaster is switched on why the thin wire inside gets very hot.
When a toaster warms up, the atoms are warmed up, by the electrons when they rub against the high resistance wire this causes the atoms to vibrate and warm up. This then transfers thermal energy to the wire.
