Experiment to Demonstrate the forces between charges

Draw a diagram of this experiment

…

Step 1

Set up apparatus as shown in A

Step 2

Attempt to bring the positively charged rod to the suspended rod (Suspended rod swings away)

Step 3

Set up apparatus as shown in B

Step 4

Attempt to bring the negatively charged rod close to the suspended rod (suspended rod swings away)

Conclusion

Like charges repel, unlike charges attract

Applications

Dust on TV screen. Static on clothes. Industrial hazards in flour mills and fuelling aircrafts

Dust on TV Screens

Dust is charged and explosive. Attracted to fat TV Screens since they were hit with an electron gun throughout the night.

Why is dust explosive?

Large surface area

What causes the static on clothes?

Friction between skin and fabric

Industrial Hazards: Fuelling aircrafts

Aircrafts need to be earthed before being refuelled because they're highly charged due to friction

How is an aircraft grounded?

Copper wire is attached from aircraft to earth to conduct electricity out

Liquids … Vapours …

Burn. Explode

Industrial Hazards: Flour Mills

Flour released as dust when blown. Charge can cause it to explode