Using Electricity Flashcards
What is the formula for current gain?
Current gain = collector current/base current
What is an iron bar with a coil around it called?
A solenoid
What is a relay?
A relay is a switch
What does a relay do?
A relay uses a small current to switch on a much larger current, typically in order to protect a user of a device which draws a large current.
What does a diode do?
It allows current to flow in only one direction.
What is adding small amounts of other elements to silicon to change its electrical properties called?
Doping
What can silicon be doped with?
Phosphorus and boron.
What is forward bias?
This allows the diode to pass current in a circuit once the voltage has equalled or exceeded about 0.7 volts in the forward bias direction.
What is reverse bias?
Where the diode will not conduct electricity until about 1000V.
What materials can magnets attract to?
- Iron
- Some steels
- Nickel
- Cobalt
What is the advantage of using a relay over a transistor?
It is more robust.
Which bias does a LED give off light in?
Forward bias.
What two things do capacitors do?
Capacitors act as energy stores and they absorb energy in case of electricity spikes.
Where are capacitors used and why?
In computers to protect delicate electrical equipment.
What is the current gain formula?
Current gain = collector current/base current
