Static Electricity Flashcards
How do objects become charged?
When they gain or lose electrons usually because of friction between insulators
State the unit for charge
Coulombs (C)
Is it easier to lose protons or electrons?
Electrons
Suggest why clothes dried in a tumble drier might stick to each other
Clothes will rub in the tumble drier
This could charge the clothes as electrons are lost when the clothes rub
Some will lose electrons (becoming positive) and others will gain electrons (becoming negative)
Clothes that are oppositely charged will attract and stick together
Name 3 uses of static electricity
Photocopying
Insecticide spraying
Paint spraying
In which direction does an electric field go?
The direction that a positively charged object would move in that point in the field
What force do charged objects exert on each other?
Electrostatic forces
These can be attractive forces or repulsive forces
Polarisation of charge
When charges move or separate in a neutral object, leaving areas of net positive or negative charge.
Like charges…
repel
Opposite (unlike) charges…
attract
Induction
Electrically charged objects can attract an uncharged object
Like charges of neutral object will be repelled leaving unlike charges on the surface (polarisation of charge)
What causes sparks?
As electric charge builds up on an object, the PD between the object and the earth (0V) increases. If PD gets large enough, electrons can jump the gap between the charged object and the earth or an earthed conductor that is nearby - this is a spark. This usually happens when the gap is small; however, lighting is just one, big spark
Explain how an aircraft can become electrically charged as it flies through the air
Friction between two electrical insulators causes the build up of static electricity
Friction between the aircraft and the air causes the loss of electrons from one (becoming positively charged) and the gain of electrons for the other (becoming negatively charged)
The aircraft, in this instance, is an electrical insulator because charge cannot flow from it to the earth
The charges of a piece of plastic and a cloth that have been rubbed together are…
Equal and Opposite
