Electricity- Triple Flashcards
1
Q
Bigger change in voltage=
A
The more energy is transferred for a given amount of charge in the circuit
2
Q
Voltage
A
Is the energy transferred per unit of charge passed
3
Q
One volt
A
One joule per coulomb
4
Q
Static electricity
A
- When two insulating materials are rubbed together and electrons will go from one material to the other
- This will leave a positive electrostatic charge on one and a negative on the other
5
Q
Electrostatic charges are produced
A
By the movement of electrons (charges don’t move)
6
Q
How can a charged conductor be discharged?
A
By connecting it to the earth with a metal strap
7
Q
Electrons flow
A
- Down if negative
2. Up if positive
8
Q
How does a spark occur?
A
If the object has a greater charge the voltage between it and the earth will be greater. If the voltage gets big enough there’s a spark which jumps across the gap
9
Q
Describe the gold-leaf electroscope
A
- When a rod with a known charge is bought near to the disk of the electroscope, electrons will either be attracted or repelled from the metal disk
- This induces a charge in the metal disk which in turn induces a charge on the gold leaves
- Both gold leaves will have the same charge so they will repel each other causing them to rise
10
Q
Ink-jet printer
A
- Tiny droplets come out of a fine nozzle making them electrically charged
- Droplets are attracted to the opposite charge plate and repelled from the other
11
Q
Lightning
A
- Rain drops and ice bump together knocking electrons
- Leaves top of the cloud positively charged and the bottom negatively charged
- This creates a huge voltage and a big spark
12
Q
Filling fuel
A
- As fuel flows out of the filter pipe static electricity builds up
- This can easily lead to a spark in dusty or fumy places
- Solution: make the nozzles out of metal to conduct the charge away instead of building it up
- Can have earth straps between the fuel strap and the fuel tank
