Electronics, static and current Electricity, Flashcards
Static electricity is caused by
Friction
If an object is positive does it have more protons or electrons?
If an object is negative “
Positive -more protons
Negative-more electron
Current
Charges flowing through a wire
Current measured in
Amps by an ampmeter or ammeter
Potential difference or voltage
Ability of the charges to do a task
Voltage measured in
VoLts by a voltmeter
Resistance
Opposition to the flow
Resistance measures in
Ohm
Ohms law
Potential difference is directly proportional to the current
Two ways of laying bulbs
In series
In parallel
Why bulbs is parallel better?
One bulb goes, the others won’t
Diode
Allows current to flow is one direction only
Diode that can flow
Forward bias
Diode than cannot flow
Reverse bias
Led
Light emitting diode
Why led good
Small amount of current
Ldr
Light dependent resister
How does an LDR work
Value of resistance changes with change in lit get intensity.
Resistance increases with low light intensity eg-street light
Effects of electricity
Heating - boil water
Chemical - electrolysis
Magnetic - electromagnet
Fuse
Limit amount of current flowing through.
Safety precaution stops overheating
Wires in a plug
Neutral- blue
Live-brown
Earth-yellow and green
Direct current
Current that flows in one direction only
Alternating current
Current that continuously changes direction
Electricity in homes ac
230v
Measure electricity in homes
Kilo watt per hour.
kWh
