Electricty/Electronics Flashcards
What is used to measure current in a circuit?
Ammeter
What is electrical current?
A flow of electrons
Current is measured in..
Amperes or Amps (A)
Voltage is measured by…
Placing a voltmeter across a component
Voltage is measured in…
Volts (V)
How does the current travel in a series circuit?
Along one path
Explain current in a series circuit
The same at every point
How is the supply voltage calculated in a series circuit?
Voltage supply = voltage 1 + voltage 2 and so on…
How does current travel in parallel circuits?
Along branches
Switches in series circuits must always be……. For the current to flow
Closed
Switches in parallel can be…..
An example of switches in parallel is…
Switched on depending on the branch
Household lighting
How do you measure resistance?
Ohmmeter
What is resistance measured in?
Ohms
What factors affect resistance?
The longer the wire the higher the resistance
The thinner the wire the higher the resistance
What happens if the resistance is increased in a circuit?
The current is decreased
What is power rating?
Which electrical energy is converted in to other forms
What is the change in a toaster? (Energy)
Electrical to heat energy
How is efficiency calculated?
%Efficiency= output/input*100
What is direct current?
Direct current is when the current in a circuit passes in one direction ONLY.
What is alternating current?
Alternating current is when the current changes direction every fraction of a second
Mains sockets supply …. volts and have a frequency of …..Hz
230v
50Hz
Explain electric fields..
Negative sign with arrows pointing towards it
Positive sign with arrows pointing away
5 positive signs point to 5 negative signs
What would a graph of a light build look like?
The radiant gradually increases as the resistance of the bulb increases as more current is passed through it.
In a plug what colour is the live wire?
Brown
In a plug the neutral wire is..
Blue
The earth wire in a plug is..
Yellow and green
What does the double insulated symbol look like?
Big square with a smaller square inside
When would a 3A fuse be used?
For power less than 700 watts
When would a 13A fuse be used?
When the power is more than 700 watts
