Electrostatics Flashcards
(47 cards)
Where are the electrons found in an atom?
Energy levels
Where are the protons and neutrons found in the atom?
Nucleus
What is the charge and relative mass of a proton?
Charge = +1
Mass = 1
What is the charge and relative mass of a neutron?
Charge = 0
Mass = 1
What is the charge and relative mass of a electron?
Charge = -1
Mass = 1/1840
2 like charges…
Repel
2 unlike charges…
Attract
A charged object and an uncharged object…
Attract
Explain what happens electrostatically when you rub a balloon on your hair.
- Electrons will move from one to the other
- One will have a positive charge and the other a negative charge
- They have opposite charges so attract each other
- The hair have the same charge so repel each other
Describe what happens when you rub a rod with a duster.
- Electrons are transferred
- One has a positive charge and one has a negative charge
What is charging by friction?
- Friction causes electrons to be transferred
- One material gains electrons and becomes negatively charged
- One material loses electrons and becomes positively charged
Explain why a persons hair ‘stands on end’ when touching the Van de Graaff generator?
- The Van de Graaff generator removes electrons and they travel out of the dome by friction
- This means the dome is positively charged
- If you touch the dome you will also loose electrons and become positively charged
- Your hairs carry the same charge and repel each other
Why may a spark be seen when a conducting sphere is placed near the Van de Graaff generator?
- Electrons jump from the sphere as they are attracted to the Van de Graaff generator
- This will cause a spark
Describe situations where electrostatics are useful.
- Painting a car with spray paint
- Smoke precipitator in a chimney
- Photocopiers
Explain how spray paint can be electrostatically charged to effectively paint a car.
- car/bike is negatively charged
- paint is positively charges
- attract
- paint spreads out as it has the same charge (even coat)
- paint will reach difficult areas
Explain how a smoke precipitator works.
- smoke particles pass near a positive grid of wires and lose electrons
- they become positive
- attract to negative metal plates (precipitated)
- plates are knocked and the particles collected
- less smoke is released so less pollution
Describe a danger of electrostatics and what can be done to prevent it.
- when filling an airplane with fuel, there may be friction
- this could cause a spark and the fuel may ignite causing an explosion
- you must earth the aircraft first to prevent this happening
Do field lines around a positive sphere point in or out?
Out
If you have two bulbs in a circuit and one breaks and the other still lights up, what kind of circuit is it?
Parallel
If you have two bulbs in a circuit and one breaks and the other also breaks, what kind of circuit is it?
Series
What does an ammeter measure in what unit?
Measure current.
How are ammeters connected in a circuit?
They are connected in series.
What is the unit of current?
Amps (I)
What happens to current in a series circuit?
It stays the same.
