Physics P4 Ocr Gateway B Exam Questions and answers, rated A+

Physics P4 Ocr Gateway B Exam Questions and answers, rated A+ What happens when two insulating materials are rubbed together?Electrons will be rubbed off one and put on to the other What charge is given when two insulating materials are rubbed together?Positive on one that has lost electrons/due to lack of electrons Negatie charge on the one that has gained electrons/excess of electrons What does the direction of the electrons transferred depend on?The two materials What can happen if enough static charge builds up?It can suddenly move which can cause sparks or shocks that can be dangerous Give 3 examples of when electricity can be a nuisance1. Attracting dust: objects that are made out of insulators eg. TV 2. Clothing clings and crackles: little sparks/shocks 3. Shocks from door handles: walk on a nylon carpet with insulating soles Give 2 ways that electricity can be dangerous1. A lot of charge built up on clothes can cause a spark and is dangerous if near inflammable gases or fuel fumes 2. Fuel filling: as fuel flows out of a filler pipe, the static can build up, can lead to a spark and cause an explosion How can dangerous sparks be prevented?Connecting a charged object to the ground using a conductor = earthing How do anti–static sprays work?By making the surface of a charged object conductive = provides an easy path for the charges to move away How do paint–sprayers work?– The spray gun and object are oppositely charged – Each paint drop repels making a very fine spray – The object attracts the paint – Gives an even coat, hardly any paint is wasted and no shadows How do dust–precipitators work?– Smoke particles meet wire grid/rods with high voltage and negative charge – Dust gain electrons = negatively charged – Dust induces a charge on