Electrostatics in the wet!
Question:
Explain why simple electrostatic experiments such as picking up bits of paper with an
electrified comb never work as well on rainy days as on dry
days.
Answer:
Wet air conducts electricity, dry air is a very
good insulator. Therefore although you can charge objects up just as well on wet days as on
dry ones the charge leaks away through the moist air to the ground really quickly on wet
days and so the experiments never work well.
This leakage of charge usually
happens so quickly on wet days that the objects never really gain much of a charge at
all.
A VERSION IN WORD IS AVAILABLE ON THE SCHOOLPHYSICS CD