Static Electricity Flashcards
How to charge an acetate rod
When the acetate rod is rubbed, the friction causes the electrons in the acetate rod to transfer to the duster.
• Acetate becomes positively charged.
Gold leaf electroscope
- Charge can be transferred to the electroscope by wiping a charged object across the cap. The charge flows over the conducting copper and gold, and the gold leafy rises as it becomes repelled by having the same charge as the copper.
- To discharge the GLE you can touch the disc and it will become earthed.
Electrostatic precipitator
- Smoke particles pick up a negative charge by going through the negatively charged grid.
- Smoke particles are attracted to the positively charged collecting played.
- Collecting played are knocked to remove the smoke particles.
Photocopier
- Copying plate is given a charge.
- An image of the page to be copied is projected onto the charged copying plate.
- Where light hits the page the charge leaks away, leaving a pattern on the page.
- Black ink powder is attracted to the charged parts of the plate.
- Black ink powder is transferred onto a piece of paper.
- The paper is heated do the powder melts and sticks to the paper.
- This is now a photocopy of the original page.
Spray painting a car
- A spray gun attached to a positive terminal of power supply causes every paint particle to become positively charged.
- The paint particles spread out because like charged repel - meaning the paint is not clumpy - even spread.
- The car door is negatively charged and therefore attracts the paint particles - meaning less paint is wasted and covers areas that are hard to reach.
Re-fuelling planes
- When refuelling an aircraft, the fuel as it’s passing through the hose rubs against the inside of the hose’s walls, causing static electricity to build up. This can cause a small spark - which then triggers an explosion and the plane will blow up.
- Thin copper wire can be put in between the plane and earth to carry the excess charge.
- The wire neutralises any charged object placed in contact with it.
Lighting
- Lighting hits the ground - electricity spreads around the object.
- Prevention of lighting dangers - shelter in an enclosed building with wiring and plumbing (can be a vehicle with a hard metal top).
- Lighting rod connected to the earth - providing the least resident path for the lighting to reach the ground.
How to charge a polythene rod
When the polythene rod is rubbed, the friction causes the electrons in the duster to transfer to the polythene rod.
• Polythene becomes negatively charged.
What happens to two oppositely charged objects?
They attract each other.
What happens to two objects of the same charge?
They repulse each other.
Why would something which has become electrically charged due to friction stay charged when it stops moving?
There would be an insulating material between the object and the ground.
