SP7b Dangers and uses of static electricity

Question 1

Explain why we get shocks from everyday objects.

Answer 1

.you can build up an unbalanced electric charge due to friction
.if you then touch a conductor, electrons will flow between you and the conductor to remove the excess
.the shock occurs from discharge (discharging excess electrons)

Question 2

How does lightening occur? (2)

Answer 2

.static builds up in clouds due to frciton between particles of ice or water moved by air currents
.when the charge is large enough, charged particles travel through the air between the cloud and the Earth

Question 3

How do electrostatic sprayers work? (3)

Answer 3

.when spraying crops with insecticide, electrodes on the spray nuzzle charge the spray droplets - droplets spread out because they repel each other
.droplets are attracted to the plants by induction
.spray spreads around the plant and less falls on the ground - less waste

Question 4

What is earthing?

Answer 4

when something is connected to the Earth by a conductor so that electric charges can flow between it and the Earth.