3881926
Description
Flashcards by charlotte.dredge, updated more than 1 year ago
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Created by charlotte.dredge
over 8 years ago
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| Question | Answer |
| How 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 |
| What 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 |
| Name 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 |
| Give a use of Static Electricity in everyday life | Electrostatic Painting = Car panel is -ve, paint is +ve. Paint spreads as +ve's repel, but stick to car as the two substances attract |
| Why 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 |
| Why 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 |
| What 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 |
| What 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 |
| Why 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 |
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