Karteikarten
P2 - Static and Current Electricity
Karten in diesem Stapel (9)
- 1How does Static Electricity occur? What happens to the charge of materials gaining/losing electrons?It occurs when friction between two insulators, and one becomes electrically charged, but the electrons are 'static'. They don't move.
Material receiving electrons = negatively charged
Material losing electrons = positively charged - 2What happens to when a charged ebonite rod is held near a suspended perspex rod? What happens when a charged perspex rod is help near a suspended perspex rod?Suspended rod is attracted
Suspended rod is repelled - 3Name two types of common electrostatic phenomina What do they have in common?Lightning = clouds charged up by rising hot air, then discharge occurs
Charged balloons = a -ve balloon held near a wall. The electrons in wall move away from surface, leaving wall +ve - attract
Both involve movement of electrons - 4Give a use of Static Electricity in everyday lifeElectrostatic Painting = Car panel is -ve, paint is +ve. Paint spreads as +ve's repel, but stick to car as the two substances attract
- 5Why and how do aircraft fuel tanks discharge unsafe static?The fuel gains electrons from fuel pipe. Fuel is now -ve, pipe is +ve
Resulting voltage causes discharge (spark), which could cause explosion
Fuel tank can be earthed with copper conductor - 6Why is earthing beneficial? What happens to electron flow if object requiring earthing is either negative or positive?It allows a constant safe discharge to occur, equalising electron imbalance - electrons can flow from one body to another
Negative - conductor will discharge electrons from object to equalise
Positive - conductor will conduct electrons from earth to equalise - 7What is a current? How is a current drawn on a circuit?It is the rate of flow of charge, which in a metal, is the flow of electrons
Greater flow of electrons, greater current
Electrons are attracted to +ve terminal, but it is drawn the other way around - 8What are the 3 types of cells and what are they used for?1. Wet cell, rechargeable -
Cars and Industry
2. Dry cell, non-rechargeable
Torches, Hearing Aids, Pace makers
3. Dry cell, rechargeable
Mobiles, Power tools - 9Why are non-rechargeable non-environmentally friendly? What's an alternative?Energy to make the cell is 50 times what it produces
Toxic chemicals such as Mercury leak into ground
They shouldn't be place in dustbins
Rechargeable batteries