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Electricity
Chapter 34
Question | Answer |
---|---|
What is current | The flow of electrons in a wire |
To make a simple circuit you need | A Battery , a bulb and some wires |
Insulators | substances that do not allow electricity to travel through them |
Conductors | substances that allow electricity through them |
To measure current use | an ammeter |
Current is measured in units called | Amps |
The symbol for current is | I |
Bulbs in series are connected | one after the other in the circuit |
Bulbs in paralled | are connected in separate circuits opposite each other |
if one bulb blows in a series circuit | they all go out |
A battery | pushes current through the wires |
Voltage is also called | Potential difference |
Voltage is measured in | Volts |
the symbol for a battery is a long line followed by a short line. the long line represents this end of the battery.. | positive |
Resistance is | the amount by which a wire tries to stop current going through it |
Resistance is measured using a device called | an ohmmeter |
units of resistance are | ohms |
There are two types of resistor | Fixed and variable |
ohms law states that | V/I = R |
a diode | is a device that allows current to flow through in one direction only |
light emitting diodes are used instead of bulbs because | they use very little electricity |
LDR stands for | Light dependent resistor |
a thermistor is | a device made of material that reduces its resistance when the temperature of the device changes |
Power is | the rate at which work is done |