C7 ELECTRICITY Flashcards
energy use to
do work / perform activity
SI unit for energy
joule (Symbol: J)
Types of energy
heat
chemical
kinectic
sound
elastic and gravitational potential
electrical
nuclear / atomic
Sources of energy
renewable sources: sun, water, wave, wind, geothermal, biomass
non-renewable sources: radioactives, fossils fuels
What is Electrostatic charges?
Electric charges that do not move freely
Electrostatic charges can be produce through?
friction (rubbing)
Proton and electron?
Proton: positive electric charge
Electron: negative
During friction, electrons…
separated and transferred from 1 object to another
Object that gains electrons(-) will become?
negatively charges
Object that lose electron(-) will become?
positively charges
Interaction between (+) and (-) will produce?
Pushing forces produces when: similar charges interact
Pulling forces produces when: different charges interact
electrostatic forces 静电
Function of electroscope (gold leaf electroscope)
detect presence存在, quantity数量 and type类型 of electrostatic charges
Why Neutral strip in electroscope not diverge?
(+) and (-) are attracted to each other
Why (+) and (-) strip diverge?
same charges repel each other
Solve daily life problems involving electrostatic
Computer become dusty easily cuz (-) on the dust are attracted to positive charges on screen
Solution: use microfibre cloth
