web viewearthing is mentioned explicitly in the ... the word 'charge' was not used very...
TRANSCRIPT
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.(2)
..............................................................................................................................................(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.
(2) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. ..............................................................................................................................................(ii) The cloth is also charged when it rubs against the plastic. Describe the charge on the cloth.
(2) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. ..............................................................................................................................................
(Total for Question is 8 marks)
Q2.
Describe one situation where separation of electric charge can create a spark.(2)
.............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. ..............................................................................................................................................
Q3.
An atom contains electrons, neutrons and protons. *The photographs show some electrostatic effects.
Explain in terms of electric charges how one of these effects is caused.You may include diagrams to help with your answers.
(6)
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Q4.
(a) A student charges two balloons and hangs them side by side.
Explain why the cotton threads are not vertical.(2)
.............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. ..............................................................................................................................................
(b) The student rubs another balloon with a cloth. This balloon becomes negatively charged.
(i) Complete the sentence by putting a cross ( ) in the box next to your answer.Compared to the charge gained by the balloon, the cloth gains
(1) A a larger negative charge B a larger positive charge C an equal negative charge D an equal positive charge
(ii) Explain why the balloon became negatively charged when it was rubbed with the cloth.(2)
.............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. ..............................................................................................................................................(iii) The student then puts this charged balloon against a metal cabinet.
Describe what happens to the charge on the balloon where it touches the metal cabinet.(2)
.............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. ..............................................................................................................................................(iv) The student charges another balloon and holds it against a wall. The charged balloon sticks to the wall when he lets go.
Suggest why the balloon is attracted to the wall.(1)
.............................................................................................................................................. ..............................................................................................................................................
(Total for Question = 8 marks)
Q5.
A battery sends a current through a metal wire. 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.
(2) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. ..............................................................................................................................................(ii) The cloth is also charged when it rubs against the plastic. Describe the charge on the cloth.
(2) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. ..............................................................................................................................................
Q6.
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.(2)
.............................................................................................................................................. .............................................................................................................................................. ..............................................................................................................................................(iii) The metal cup does not become charged when she rubs the trophy. Suggest why the cup does not become charged.
(2) .............................................................................................................................................. .............................................................................................................................................. ..............................................................................................................................................(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)
Q7.
The student rubs another balloon with a cloth. This balloon becomes negatively charged.
(i) Complete the sentence by putting a cross ( ) in the box next to your answer.Compared to the charge gained by the balloon, the cloth gains
(1) A a larger negative charge B a larger positive charge C an equal negative charge D an equal positive charge
(ii) Explain why the balloon became negatively charged when it was rubbed with the cloth.(2)
.............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. ..............................................................................................................................................(iii) The student then puts this charged balloon against a metal cabinet.
Describe what happens to the charge on the balloon where it touches the metal cabinet.(2)
.............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. ..............................................................................................................................................(iv) The student charges another balloon and holds it against a wall. The charged balloon sticks to the wall when he lets go.
Suggest why the balloon is attracted to the wall.(1)
.............................................................................................................................................. ..............................................................................................................................................
Q8.
An atom contains electrons, neutrons and protons.(a) Use words from the box to complete the sentences.
(i) The charge on an electron is . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
(1)(ii) An electron has a mass that is . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
(1)(b) At a petrol station, a pipe is used to transfer petrol to the storage tanks.The pipe is earthed.There is friction between the petrol and the end of the pipe.
(i) Explain why it is dangerous not to earth the pipe.(2)
.............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. ..............................................................................................................................................
(ii) Explain how earthing the pipe makes this process much safer.(2)
.............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. ..............................................................................................................................................
*(c) The photographs show some electrostatic effects.
Explain in terms of electric charges how one of these effects is caused.You may include diagrams to help with your answers.
(6)
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(Total for Question is 12 marks)
Q9.
(a) 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.(2)
.............................................................................................................................................. .............................................................................................................................................. ..............................................................................................................................................(iii) The metal cup does not become charged when she rubs the trophy. Suggest why the cup does not become charged.
(2) .............................................................................................................................................. .............................................................................................................................................. ..............................................................................................................................................(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)
(b) Describe one situation where separation of electric charge can create a spark.(2)
.............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. ..............................................................................................................................................
(Total for Question = 8 marks)
Examiner's Report
Q1.
(b) This question provided a straightforward start to the paper, requiring the use of the equation relating charge, current and time. The vast majority of candidates scored both marks. Of those who did not, working was rarely shown. This removed the opportunity of scoring 1 mark.
Results Plus: Examiner CommentsThis response gives the correct answer with the working clearly shown. Both marks were awarded.
Results Plus: Examiner TipAlways show your working, even in the simplest of calculations.
(c) In this question examiners were looking for statements about electrons being transferred from the cloth to the rod, leaving the cloth with an equal but opposite charge to the rod. Most candidates scored 3 marks, mainly missing out on the 'equal' mark. Very few scored all 4 marks.
Results Plus: Examiner CommentsThis is a well-structured response which scored all 4 marks.
Q2.
There were 2 marks for this item - for stating the situation and for stating between which objects/people the spark passed. One of the most common answers referred to lightning passing from a charged cloud to the ground.
Other acceptable examples included pulling clothes off over your head and touching a car when charged up because of contact between driver's clothes and seat. Pressing on/off light switches was not accepted and nor were references to sparks caused by high temperatures.
Results Plus: Examiner CommentsThe situation was clearly explained. There was sufficient to score the second mark because there was linkage between the charged person and the door handle.
Sometimes, the situation was ambiguous.
Results Plus: Examiner CommentsHere it was not clear who or what was charged but there was enough to score the second mark, only.
Q3.
Some candidates did not read the question carefully and tried to provide an explanation for all three situations and then often got into a tangle. Others decided to start by explaining how the balloon or rod would be charged and sometimes mentioned movement of electrons at this stage. This was not asked for and they again got into a tangle trying to explain that rubbing the balloon on the hair would charge both the balloon and hair.
The best responses stated clearly that opposite charges attract and then described the effect they had on the hair, paper or water. A few had never seen water being attracted and despite the picture gave a description to explain why it curved away.
There was a great deal of incorrect science demonstrated in answers to this question but in most cases candidates were able to identify an object that was positively charged and one that was negatively charged and stated there was an attraction because opposite charges attract. Most candidates assumed that the hair, paper and water all had charges and did not consider induction, but diagrams sometimes showed the separation of charges which was worthy of credit.
Results Plus: Examiner CommentsThis answer describes an effect of charging a balloon even though it does not use an example shown in the photographs. The diagram also shows charge on the balloon although it is incorrect on the wall. This is a Level 1 response which was awarded 2 marks.
Results Plus: Examiner CommentsThis answer explains that the hair must be negatively charged but does not consider how it acquired this charge. It then states that negative and positive charges attract. This is a Level 2 response that was awarded 4 marks.
Results Plus: Examiner CommentsThis answer not only includes attraction between positive and negative charge but also explains that the hair spreads out because the negative charges repel. This part of the answer is Level 2. The answer also includes transfer of electrons causing the charge and the diagram shows charge separation for the balloon near the wall. This takes the answer to Level 3 and 6 marks are awarded.
Results Plus: Examiner TipAccurate diagrams are very useful when concepts are difficult to explain in words.
Q4.
a Most candidates correctly stated that the two balloons repelled each other. Better candidates could state that this was because they both had the same charge. At this stage in the question the nature of the charge had not been declared and examiners would accept 'both had positive charge' or 'both had negative charge'. There is still some misunderstanding of the term static with answers such as 'both balloons have static' being fairly common.
Results Plus: Examiner CommentsA good, clear answer which scored both marks.
Results Plus: Examiner CommentsThis scored a mark for the idea that the balloons were pushing each other away, but static charge is too vague for the other mark.
Results Plus: Examiner CommentsThis gets a mark for writing that the balloons have the same charge but does not actually state that the balloons repel and so did not get the other mark.
bii At this stage in the question, candidates had been told that the balloon had a negative charge and so answers which tried to give the balloon a positive charge could not be accepted. Those who appreciated that electrons could be transferred usually went on to give the correct direction from cloth to balloon: unlike candidates who thought that positive charge moved ( either 'positive electrons' or 'protons' ). Surprisingly few candidates mentioned friction even though this is clearly mentioned in the specifications. This would have given a mark regardless of any subsequent errors in nature and direction of charge movement.
Results Plus: Examiner CommentsA good, clear answer which scored two marks.
biii-iv In part iii, many candidates seemed to miss the point that the cabinet was metal and tried to describe the balloon being attracted or repelled. Examiners were looking for responses which described the movement of charge from balloon to cabinet. Failure to mention the nature of the charge was not penalised but an incorrect statement that positive charge moved was not accepted. Earthing is mentioned explicitly in the specification and candidates who correctly used this term scored a mark. The flow of electrons in a metal is also in the specification and mention of this scored a mark.
In part iv, examiners were looking for either correct use of the term induction or a description in terms of charge separation at the surface of the wall. It was pleasing to see that a good many candidates were able to give a very clear description of this process. Candidates who wrote that the wall had a positive charge without directly specifying that this was at the surface, were given the benefit of the doubt. Candidates who only stated that 'opposite charges attract' did not give sufficient detail to score a mark.
Results Plus: Examiner CommentsThis response easily made all of the possible mark points in the first part. The description of electrostatic induction is good and is typical of many responses seen.
Q5.
In this question examiners were looking for statements about electrons being transferred from the cloth to the rod, leaving the cloth with an equal but opposite charge to the rod.
Most candidates scored 3 marks, mainly missing out on the 'equal' mark. Very few scored all 4 marks.
Results Plus: Examiner CommentsThis is a well-structured response which scored all 4 marks.
Q6.
(ii) This question was mainly based on the act of cleaning a trophy which comprises a metal cup on a plastic base.
Results Plus: Examiner CommentsMany demonstrated a clear link between the thing moving and the direction. Some were more vague and omitted the words 'the base of' from a response such as that shown. Others scored the second mark using the (loose) idea of friction. There were the usual incorrect references to positive electrons and proton movement.
Results Plus: Examiner TipTake every opportunity to reinforce the concept that it is the negative electrons which move, either in electrostatics or when there is a current in a wire. Only in electrolysis, really, do positive charges move. Refer to the structure of the atom to provide a reason for this. (See also comments for 3bi.)
(iii) Normally, 'suggest' questions are worth a single mark. This particular item was worth two marks.
Results Plus: Examiner CommentsThis response was only worth 1 mark. It is insufficient to say either 'metals are conductors' or 'the cup is earthed'. Both of these ideas are necessary for the suggestion. Misconceptions were rife. For example: some candidates referred to 'the base is earthed' others contradicted themselves by writing 'as metals are conductors, the electrons are held tightly in place' a common lack of precision was that 'metals are not insulators', which is not the same as 'metals are conductors' metals can be charged provided they are insulated. Note this is different from saying they are insulators.
Results Plus: Examiner TipRead through your answer at the end if you have time. Make sure you have not contradicted yourself.
In contrast, this example contains both ideas even though not well expressed.
Results Plus: Examiner CommentsThis was awarded 2 marks.
Results Plus: Examiner TipThis example is suitable for presenting to students, during lessons, in a variety of redacted forms, to illustrate linguistic points. The idea of precision in writing is returned to in item 2cii.
Q7.
ii At this stage in the question, candidates had been told that the balloon had a negative charge and so answers which tried to give the balloon a positive charge could not be accepted. Those who appreciated that electrons could be transferred usually went on to give the correct direction from cloth to balloon: unlike candidates who thought that positive charge moved ( either 'positive electrons' or 'protons' ). Surprisingly few candidates mentioned friction even though this is clearly mentioned in the specifications. This would have given a mark regardless of any subsequent errors in nature and direction of charge movement.
Results Plus: Examiner CommentsA good, clear answer which scored two marks.
iii-iv In part iii, many candidates seemed to miss the point that the cabinet was metal and tried to describe the balloon being attracted or repelled. Examiners were looking for responses which described the movement of charge from balloon to cabinet. Failure to mention the nature of the charge was not penalised but an incorrect statement that positive charge moved was not accepted. Earthing is mentioned explicitly in the specification and candidates who correctly used this term scored a mark. The flow of electrons in a metal is also in the specification and mention of this scored a mark.
In part iv, examiners were looking for either correct use of the term induction or a description in terms of charge separation at the surface of the wall. It was pleasing to see that a good many candidates were able to give a very clear description of this process. Candidates who wrote that the wall had a positive charge without directly specifying that this was at the surface, were given the benefit of the doubt. Candidates who only stated that 'opposite charges attract' did not give sufficient detail to score a mark.
Results Plus: Examiner CommentsThis response easily made all of the possible mark points in the first part. The description of electrostatic induction is good and is typical of many responses seen.
Q8.
(a)(i) Most candidates knew that electrons had a negative charge and so scored the mark for this question.
(a)(ii) The majority of candidates knew that the mass of an electron is much smaller than the mass of a neutron.
(b)(i)The word 'charge' was not used very often but most candidates managed to gain marks for knowing that a spark was likely to be produced and this could cause a fire or explosion. The incorrect answer that was most frequently given was that there was a danger of electrocution.
Results Plus: Examiner Comments1 mark was awarded for 'cause a spark'
Results Plus: Examiner CommentsThis answer is typical of those that scored both marks.
Results Plus: Examiner CommentsThis is a well-organised answer, which explains that charges jump and produce a spark. It was awarded both marks.
(b)(ii)Candidates had to explain 'earthing' in terms of charge or electrons being removed, but many were reluctant to mention charge and often referred to static electricity. There was also a minority of candidates who did not understand the term 'earthing' and thought that it meant the petrol was being put into the ground and so it would be safer if it caught fire.
Results Plus: Examiner CommentsThis response mentions charge and where it is going so both marks were awarded.
Results Plus: Examiner CommentsNo marks were awarded here; the candidate does not understand the meaning of 'earthing'.
Results Plus: Examiner CommentsThis response gives electricity, which is not acceptable instead of charge. The first marking point was not given. However, 'will be sent straight to the ground' is acceptable for 'is removed' so the second marking point was awarded and the answer scored 1 mark overall.
(c)Some candidates did not read the question carefully and tried to provide an explanation for all three situations and then often got into a tangle. Others decided to start by explaining how the balloon or rod would be charged and sometimes mentioned movement of electrons at this stage. This was not asked for and they again got into a tangle trying to explain that rubbing the balloon on the hair would charge both the balloon and hair.
The best responses stated clearly that opposite charges attract and then described the effect they had on the hair, paper or water. A few had never seen water being attracted and despite the picture gave a description to explain why it curved away.
There was a great deal of incorrect science demonstrated in answers to this question but in most cases candidates were able to identify an object that was positively charged and one that was negatively charged and stated there was an attraction because opposite charges attract. Most candidates assumed that the hair, paper and water all had charges and did not consider induction, but diagrams sometimes showed the separation of charges which was worthy of credit.
Results Plus: Examiner CommentsThis answer describes an effect of charging a balloon even though it does not use an example shown in the photographs. The diagram also shows charge on the balloon although it is incorrect on the wall. This is a Level 1 response which was awarded 2 marks.
Results Plus: Examiner CommentsThis answer explains that the hair must be negatively charged but does not consider how it acquired this charge. It then states that negative and positive charges attract. This is a Level 2 response that was awarded 4 marks.
Results Plus: Examiner CommentsThis answer not only includes attraction between positive and negative charge but also explains that the hair spreads out because the negative charges repel. This part of the answer is Level 2. The answer also includes transfer of electrons causing the charge and the diagram shows charge separation for the balloon near the wall. This takes the answer to Level 3 and 6 marks are awarded.
Results Plus: Examiner TipAccurate diagrams are very useful when concepts are difficult to explain in words.
Q9.
(a) (ii) This question was mainly based on the act of cleaning a trophy which comprises a metal cup on a plastic base.
Results Plus: Examiner CommentsMany demonstrated a clear link between the thing moving and the direction. Some were more vague and omitted the words 'the base of' from a response such as that shown. Others scored the second mark using the (loose) idea of friction. There were the usual incorrect references to positive electrons and proton movement.
Results Plus: Examiner TipTake every opportunity to reinforce the concept that it is the negative electrons which move, either in electrostatics or when there is a current in a wire. Only in electrolysis, really, do positive charges move. Refer to the structure of the atom to provide a reason for this. (See also comments for 3bi.)
(a) (iii) Normally, 'suggest' questions are worth a single mark. This particular item was worth two marks.
Results Plus: Examiner CommentsThis response was only worth 1 mark. It is insufficient to say either 'metals are conductors' or 'the cup is earthed'. Both of these ideas are necessary for the suggestion. Misconceptions were rife. For example: some candidates referred to 'the base is earthed' others contradicted themselves by writing 'as metals are conductors, the electrons are held tightly in place' a common lack of precision was that 'metals are not insulators', which is not the same as 'metals are conductors' metals can be charged provided they are insulated. Note this is different from saying they are insulators.
Results Plus: Examiner TipRead through your answer at the end if you have time. Make sure you have not contradicted yourself.
In contrast, this example contains both ideas even though not well expressed.
Results Plus: Examiner CommentsThis was awarded 2 marks.
Results Plus: Examiner TipThis example is suitable for presenting to students, during lessons, in a variety of redacted forms, to illustrate linguistic points. The idea of precision in writing is returned to in item 2cii.
(b) There were 2 marks for this item - for stating the situation and for stating between which objects/people the spark passed. One of the most common answers referred to lightning passing from a charged cloud to the ground.
Other acceptable examples included pulling clothes off over your head and touching a car when charged up because of contact between driver's clothes and seat. Pressing on/off light switches was not accepted and nor were references to sparks caused by high temperatures.
Results Plus: Examiner CommentsThe situation was clearly explained. There was sufficient to score the second mark because there was linkage between the charged person and the door handle.
Sometimes, the situation was ambiguous.
Results Plus: Examiner CommentsHere it was not clear who or what was charged but there was enough to score the second mark, only.
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 calculation scores 2 marks
(2)
(c)(i) Correct responses can be seen in (i) or (ii) An explanation linking electrons (1)and one of removed by friction (1)
(transferred) to plastic (1)
["positive electrons/ protons moving", seen anywhere in part (i) or (ii) loses this mark] ignore reference to charge before rubbing transferred from cloth
(2)
(c)(ii) opposite to charge on plastic (1) equal to charge on the plastic (1)
charge on cloth is positive same size as charge on plastic electrons transferred from the cloth equal to electrons lost by cloth
(2)
Total question = 8 marks
Q2.
Answer Acceptable answers
Mark
A description to examples (2)
include the situation which caused the charge separation (1) where the spark travelled from or to(1)
when refuelling, spark between end of fuel/pipe and vehicle =2 spark between/from /to person comb/clothes/metal handle and, when combing hair/removing clothing/opening door = 2 lightning flash, between cloud and cloud/plane/ground, =2 ignore between plug and socket/jump leads
Q3.
Indicative Content Mark
An explanation etc. including some of the following points static electricity opposites charges attract charges are different induced charges
charges separate charges move electrons move electrons move towards a positive charge / balloon / rod
Allow credit for a correct explanation for an effect which is not given in the question. Allow credit for separation of charge being shown on a diagram.
(6)
Level 0 No rewardable content1 1 - 2
a limited explanation. Explains the effect is caused by charges. e.g. the charge on the balloon pulls the water; the charge on the rod attracts the bits of paper; the balloon is rubbed to give it charge; opposites attract; positive and negative attract; the answer communicates ideas using simple language and uses limited scientific terminology spelling, punctuation and grammar are used with limited accuracy
2 3 - 4 a simple explanation. Explains an effect is caused by opposite charges attracting or like charges repelling. e.g. the charge on the balloon is opposite to the charge on the water so they attract; the positive charges on the balloon attract negative charges on the girl's hair; the answer communicates ideas showing some evidence of clarity and organisation and uses scientific terminology appropriately spelling, punctuation and grammar are used with some accuracy
3 5 - 6 a detailed explanation. Explains the effect is caused by induction, charge separation or moving electrons which leads to attraction between opposite charges. e.g. the electrons have been moved off the balloon so it has a positive charge and attracts the negative charge on the hair; the balloon has a positive charge and induces a negative charge on the stream of water which attracts it; the answer communicates ideas clearly and coherently uses a range of scientific terminology accurately spelling, punctuation and grammar are used with few errors
Q4.
Answer Acceptable answers
Mark
(a) an explanation linking: balloons repel (1) (because) they have like charges (1)
balloons repulse / push away (from each other/to the side) same charge / both positive / both negative accept like charges repel for 2 marks (2)
(b)(i) D an equal positive charge
(1)
(b)(ii) an explanation linking any two of friction (between cloth and balloon) (1) transfer of electrons (1) (electrons/negative charges move) from cloth to balloon (1)
charge/electrons move accept balloon gains electrons from the cloth for 2 marks
(2)(b)(iii) a description
including two from the following: balloon becomes discharged (1) metal /cabinet is a conductor (1) electrons move through / on to metal / cabinet (1)
earthed / neutral (negative) charge for electrons accept electrons move to earth for 2 marks
(2)(b)(iv) (surface of) wall
(becomes) positively charged /charged by induction (1)
charges on the wall separate charge closest to the surface of the wall is opposite to the
(1)
charge on the balloon
Q5.
Answer Acceptable answers
Mark
(i) Correct responses can be seen in (i) or (ii) An explanation linking electrons (1)and one of removed by friction (1)
(transferred) to plastic (1)
["positive electrons/ protons moving", seen anywhere in part (i) or (ii) loses this mark] ignore reference to charge before rubbing transferred from cloth
(2)
(ii) opposite to charge on plastic (1) equal to charge on the plastic (1)
charge on cloth is positive same size as charge on plastic electrons transferred from the cloth equal to electrons lost by cloth
(2)
Q6.
Answer Acceptable answers
Mark
(i) B electrons (1)(ii)
An explanation linking (negative) electrons transfer (1) because of friction/from cloth (to base) (1)
negative charge (reject protons and positive charge for this mp) moves cloth loses electrons/negative charge (to base) = 2 (2)
(iii)A suggestion to include charge (any) could move through cup /metal (1) (cup is) earthed (1)
cup/metal is a conductor ignore metal is not an insulator to earth/ ground / to/ through student's hand (2)
(iv)
(1)
Q7.
Answer Acceptable answers
Mark
(i) D an equal positive charge
(1)
(ii) an explanation linking any two of friction (between cloth and balloon) (1) transfer of electrons (1) (electrons/negative charges move) from cloth to balloon (1)
charge/electrons move accept balloon gains electrons from the cloth for 2 marks
(2)(iii) a description
including two from the following: balloon becomes discharged (1) metal /cabinet is a conductor (1) electrons move through / on to metal / cabinet (1)
earthed / neutral (negative) charge for electrons accept electrons move to earth for 2 marks
(2)(iv) (surface of) wall
(becomes) positively charged /charged by induction (1)
charges on the wall separate charge closest to the surface of the wall is opposite to the charge on the balloon (1)
Q8.
Answer Acceptable answers
Mark
(a)(i) negative (1) (1)(a)(ii) (much) smaller than
a neutron (1)
(1)
(b)(i) An explanation linking (friction/it) produces charges (at the end of the pipe) (1) charge jumps to fuel tank (1) (charge/friction) causes a spark (1) can cause a fire /explosion (1)
static (electricity) builds up
(2)
(b)(ii) An explanation linking (excess) charge / electrons (1)
Removed/ conducts away (1)
static charge discharged/ neutralised discharge current scores both marks
(2)
Indicative Content Mark
QWC *(c) An explanation etc. including some of the following points static electricity opposites charges attract charges are different induced charges
charges separate charges move electrons move electrons move towards a positive charge / balloon / rod
Allow credit for a correct explanation for an effect which is not given in the question. Allow credit for separation of charge being shown on a diagram.
(6)
Level 0 No rewardable content
1 1 - 2 a limited explanation. Explains the effect is caused by charges. e.g. the charge on the balloon pulls the water; the charge on the rod attracts the bits of paper; the balloon is rubbed to give it charge; opposites attract; positive and negative attract; the answer communicates ideas using simple language and uses limited scientific terminology spelling, punctuation and grammar are used with limited accuracy
2 3 - 4 a simple explanation. Explains an effect is caused by opposite charges attracting or like charges repelling. e.g. the charge on the balloon is opposite to the charge on the water so they attract; the positive charges on the balloon attract negative charges on the girl's hair; the answer communicates ideas showing some evidence of clarity and organisation and uses scientific terminology appropriately spelling, punctuation and grammar are used with some accuracy
3 5 - 6 a detailed explanation. Explains the effect is caused by induction, charge separation or moving electrons which leads to attraction between opposite charges. e.g. the electrons have been moved off the balloon so it has a positive charge and attracts the negative charge on the hair; the balloon has a positive charge and induces a negative charge on the stream of water which attracts it; the answer communicates ideas clearly and coherently uses a range of scientific terminology accurately spelling, punctuation and grammar are used with few errors
Total marks for question = 12
Q9.
Answer Acceptable answers
Mark
(a)(i) B electrons (1)(a)(ii)
An explanation linking (negative) electrons transfer (1) because of friction/from cloth (to base) (1)
negative charge (reject protons and positive charge for this mp) moves cloth loses electrons/negative charge (to base) = 2 (2)
(a)(iii)
A suggestion to include charge (any) could move through cup /metal (1) (cup is) earthed (1)
cup/metal is a conductor ignore metal is not an insulator to earth/ ground / to/ through student's hand (2)
(a)(iv)
(1)(b)
A description to include the situation which caused the charge separation (1) where the spark travelled from or to(1)
examples when refuelling, spark between end of fuel/pipe and vehicle =2 spark between/from /to person comb/clothes/metal handle and, when combing hair/removing clothing/opening door = 2 lightning flash, between cloud and cloud/plane/ground, =2 ignore between plug and socket/jump leads (2)