Questions Q1. A battery sends a current through a metal wire. (a) (i) Complete the sentence by putting a cross ( ) in the box next to your answer. Direct current is movement of charge (1) A backwards and forwards B in many directions C in one direction D up and down (ii) Complete the sentence by putting a cross ( ) in the box next to your answer. The particles that flow in the metal wire are (1) A atoms B electrons C protons D neutrons (b) The current in a wire is 3.7 A. Calculate the charge that flows into the wire in 13 s. charge = C
(c) Plastic is an insulator. A student rubs a piece of plastic with a cloth. This gives the plastic a negative charge. (i) Explain how the plastic is charged by the rubbing. (ii) The cloth is also charged when it rubs against the plastic. Describe the charge on the cloth. (Total for Question is 8 marks) Q2. Waste gases contain smoke particles. The diagram shows how smoke particles can be removed from waste gases as they rise through a chimney.
When the smoke particles go through the metal grid they become negatively charged. There is a current of 1.4 A between the grid and the plates. (i) Calculate the charge transferred by this current in two minutes. State the unit. (3) charge =... unit... (ii) The potential difference between the grid and the plate is 400 V. Calculate the electrical energy transferred in two minutes. energy transferred =... joules Q3. A student is investigating a filament lamp. (a) (i) Complete the sentence by putting a cross ( ) in the box next to your answer. The current in the filament lamp is a flow of
(1) A protons B neutrons C electrons D atoms (ii) The student uses this circuit in his investigation. State what is measured by the meters. Meter 1 measures... Meter 2 measures... (b) The normal operating potential difference (voltage) and current of the filament lamp is 6 V, 0.4 A. Calculate the energy supplied to the lamp under these conditions in 20 s. energy =... J (c) The graph shows how current varies with potential difference (voltage) for another filament lamp.
Calculate the resistance of the lamp when the current in the lamp is 0.3 A. resistance = potential difference current (R = V / I) (3) resistance =... Ω (Total for Question = 8 marks) Q4. Electrostatic discharge (a) Marie works in an office which has a nylon carpet. She walks across the carpet towards her filing cabinet. There is friction between her shoes and the carpet. When she touches the metal handle of her filing cabinet she feels an electric shock. (i) State the name of the charged particles which have been transferred between the carpet and her shoes. (1)... (ii) The following sentences explain how Marie got the electric shock. The sentences are in the wrong order. Put them in the correct order by numbering the boxes. Two have been done for you.
actions order in which the actions happen Marie walks across the nylon carpet 1 charge flows from Marie to the filing cabinet Marie touches the handle 4 charge is transferred by friction on to Marie Marie has lost her negative charge a negative charge builds up on Marie (b) Marie has another filing cabinet which has a black conductive strip at the top. This black strip helps to prevent electric shocks. This strip has a high resistance but still conducts charge. If Marie touches the strip before touching the handle she does not feel a shock. Explain, using the idea of electric current, why Marie does not feel a shock. (3).................. *(c) Sparks from electrostatic discharge can sometimes be very dangerous. They can cause a fire or an explosion. Safety precautions are taken to reduce risks. Explain how safety precautions, in a particular situation, reduce the risks of fire or explosion.
You may draw a labelled diagram to help with your answer. (6).................................... Q5. An electrostatic air filter is designed to remove dust particles from the air in a room. A fan blows dusty air past several metal rods and metal plates. There is a large potential difference (voltage) between the metal rods and the metal plates.
(a) Complete the sentence by putting a cross ( ) in the box next to your answer. When dusty air goes past the metal rods, the dust particles become negatively charged. This is because the dust particles (1) A B C D lose electrons lose protons gain electrons gain protons (b) When the dusty air flows past the metal plates, the dust particles settle on the metal plates. Explain why the dust particles settle on the metal plates............. (c) (i) State what happens to the charge on the dust particles when they settle on the metal plates.
(1)...... (ii) Explain why the charge does not build up on the metal plates............. (d) There is a current of 1.2 ma in the circuit. Calculate the charge transferred by this current in 40 s. State the unit. charge transferred =... unit:... (3) Q6. A lightning strike on a metal tower can be described as follows. In the cloud. A thunder cloud contains moving ice particles. Some of these ice particles are negatively charged and some are positively charged. The negatively charged particles move to the bottom of the cloud.
When the charged cloud is over the metal tower. A charge builds up on the top of the metal tower as the cloud passes over. During the lightning flash. Eventually a flash of lightning travels between the cloud and the tower. (i) Which row of this table is correct when the cloud is over the top of the tower before the lightning flash? Put a cross ( ) in the box next to your answer. (1) charge on top of the cloudcharge on top of the is tower is A negative negative B negative positive C positive positive D positive negative (ii) Here are fourstatements. Threeof these are a reason for what happens at each stage. Choose the best reason for each of the stages listed below by writing its number in the box next to the description of what happens. One has been done for you. A reason can only be used once.
(iii) Explain what happens to the charge on the metal tower as a result of the lightning flash. Q7. A student wins a trophy. It is a metal cup on a black plastic base. The student cleans the trophy. She holds one of the metal handles and rubs the rest of the trophy with a dry cloth. (i) Complete the sentence by putting a cross ( ) in the box next to your answer. The plastic base becomes negatively charged because it gains
(1) A atoms B becquerel C einstein D radium (ii) Explain why the base gains a negative charge when she rubs the trophy with the cloth. (iii) The metal cup does not become charged when she rubs the trophy. Suggest why the cup does not become charged. (iv) Some dust particles in the air drift near to the plastic base just after she cleans the trophy. Which diagram shows the correct distribution of charges on a dust particle near to the charged plastic base? Put a cross ( ) in the box next to your answer. (1)
Mark Scheme Q1. Answer Acceptable answers Mark (a)(i) C (1) (a)(ii) B (1) (b) substitution (1) 3.7 x 13 evaluation (1) 48 (C) 48.1 Correct answer with no (c)(i) calculation scores 2 marks Correct responses can be seen in (i) or (ii) An explanation linking ["positive electrons/ protons moving", seen anywhere in part (i) or (ii) loses electrons (1) this mark] and one of removed by friction (1) (transferred) to plastic (1) (c)(ii) opposite to charge on plastic (1) equal to charge on the plastic (1) ignore reference to charge before rubbing transferred from cloth charge on cloth is positive same size as charge on plastic
electrons transferred from the cloth equal to electrons lost by cloth Total question = 8 marks Q2. Question Answer Acceptable answers Mark Number (i) substitution (1) give full marks for correct answer with (3) 1.4 60 2 correct unit, no working evaluation (1) = 168 unit (1) coulombs / C Question Answer Acceptable answers Mark Number (ii) substitution (1) give full marks for correct answer, no 1.4 400 60 2 working evaluation(1) 67 200 (J) Q3.
Q4. Question Answer Acceptable answers Mark Number (a)(i) electrons (1) Question Answer Acceptable answers Mark Number (a)(ii) row 4 and 6 labelled 2,3 (1) row 2 and 5 labelled 5,6 (1) Question Number (b) Answer Acceptable answers Mark An explanation linking three of the following (3) charge flows from Marie through the
conductive strip (1) this constitutes an electric current (1) the (relatively) high resistance of the strip means that the current is (relatively) small (1) compared with the (larger) current which would flow through the metal handle (1) idea of earthing (1) Marie no longer charged when she touches the handle (1) Question Indicative content Number QWC *(c) An explanation linking some of the following points Mark (6) a clear statement of the situation being considered an explanation of how the electrostatic charge would build up if no safety precaution was taken an explanation of why a spark is generated a statement about the consequences of this spark resulting in the ignition of the {combustible / flammable} source detail of the safety precaution an explanation of electrostatic processes with the safety precaution in place.
a statement that the previously identified risk is now reduced Level 0 No rewardable material 1 1-2 a simple explanation or a diagram of a potentially dangerous situation with either a statement of a possible consequence or a relevant safety precaution the student uses everyday language and the response lacks clarity and organisation 2 3-4 spelling, punctuation and the rules of grammar are used with limited accuracy some explanation or a partially labelled diagram of the situation and some explanation of how the charge would build up in the unprotected situation linked to a relevant safety precaution or an explanation of how this results in a controlled discharge or prevents the charge separation in the first place the student uses some technical terms and shows some clarity and organisation spelling, punctuation and the rules of grammar are used with some accuracy 3 5-6 a detailed explanation or a fully labelled diagram of the situation and explanation of how the charge would build up in the unprotected situation clearly linked to a relevant safety precaution and explanation of how this results in a controlled discharge or prevents the charge separation in the first place the student uses a range of technical terms and shows good clarity and organisation spelling, punctuation and the rules of grammar are used with considerable accuracy Q5.
Q6. Answer Acceptable answers Mark C (1) (ii) In the cloud : reason 3 (1) At the tower: reason 2
Powered by TCPDF (www.tcpdf.org) (iii) (1) An explanation linking the charge was neutralised (1) by a transfer/flow of electrons (1) Discharged/ becomes zero gained electrons / negative charge Q7. Answer Acceptable answers Mark (i) B electrons (1) (ii) An explanation linking (iii) (negative) electrons transfer (1) negative charge (reject protons and positive charge for this mp) moves because of friction/from cloth (to base) (1) cloth loses {electrons/negative charge} (to base) = 2 A suggestion to include cup/metal is a conductor ignore metal is not an insulator charge (any) could move through cup /metal (1) to {earth/ ground} / {to/ through} (cup is) earthed (1) student's hand (iv) (1)