Electronics Flashcards
Name some devices that work by electronics?
Lots of mdern devices such as TV’s, digital watches, MP3 players, mobile phones and computers work by electronics
What is a diode?
A diode is a component that will allow current to flow in one direction only.
What is forward biased?
If the positive end of a battery is connected to the positive end of a diode the diode is said to be forward biased and current can flow
when the positive end of a battery is connected to the positive end of a diode and current can flow it is said to be what?
forward biased
What is electronics?
The careful and exact control of tiny amounts of electric current
what is reverse biased?
If the positive end of the battery is connected to the negative end of the diode and no electricity can flow
If the positive end of the battery is connected to the negative end of the diode and no current can flow it is said to be what?
reverse biased
What do we call it when a diode is connected to a battery but electricity cannot flow?
reverse biased
What do we call it when a diode is connected to a battery and electricity can flow?
forward biased
what can a diode be used for?
to change alternating current into direct current
What electronic devices need low voltage direct current?
Devices such as radios, tape recorders and calculators
what type of electricity would devices like radios, tape recorders and calculators need?
low voltage direct current
What is an LED?
A light emitting diode is a diode that gives out light when a current flows through it
what do we need an LED to be for current to be able to flow?
forward biased
Describe the currents that LED’s use?
tiny currents
What does an LED need because it only uses tiny currents?
a resistor to be connected in series with it
Why are LED’s useful?
They are cheap, reliable and long lasting and use far less current than other light bulbs.
do LED’s use more or less current than other lightbulbs?
less
What is a LDR?
A light dependent resistor is a resistor whose resistance depends on light
What happens when light falls on an LDR?
It’s resistance decreases, this low resistance will allow a current through the circuit
How does a LDR work?
When light falls on an LDR its resistance decreases which allows a current to flow through the circuit
Describe the type of energy that comes from the ESB mains supply
A high voltage alternating current
How do electronic devices that use low voltage electric current get their electricity?
They work off the main ESB supply which is a high voltage alternating current because they have an adaptor built into them
what do electronic devices that use low voltage electric current need to be able to use the elctricity from the ESB mains supply? Why?
electronic devices that use low voltage electric current
