Waves Final Review. Name: Date: 1. On which one of the following graphs is the wavelength λ and the amplitude a of a wave correctly represented?

Transcription

1 Name: Date: Waves Final Review 1. On which one of the following graphs is the wavelength λ and the amplitude a of a wave correctly represented? A. Displacement λ a Distance along wave B. Displacement λ a Distance along wave C. Displacement λ a Distance along wave D. Displacement λ a Distance along wave 1

2 2. A transverse travelling wave has amplitude A and wavelength λ. The distance between a crest and its neighbouring trough, measured in the direction of energy transfer of the wave is equal to A. A. B. 2A. C. λ. 2 D. λ. 3. Which of the following best describes the wave speed of a progressive wave travelling through a medium? A. The maximum speed of the vibrating particles of the medium B. The average speed of the vibrating particles of the medium C. The speed of the medium through which the wave travels D. The speed of transfer of energy through the medium 4. The diagram below shows the displacement-position graph at a particular instant for a longitudinal wave travelling along a spring. displacement to right + C displacement to left B D A position A positive displacement on the graph indicates that the coils of the spring are displaced to the right of their equilibrium position. At which position along the spring is the displacement of two adjacent coils a maximum? A. A B. B C. C D. D 2

3 5. The diagram shows the variation with distance x along a wave with its displacement d. The wave is travelling in the direction shown. d direction of travel x The period of the wave is T. Which one of the following diagrams shows the displacement of the wave at T later? 4 A. d B. d x x C. d D. d x x 6. The graph below shows the variation of air pressure with distance along a wave at one given time. The arrow indicates the direction of travel of the wave. air pressure + normal air pressure P distance along wave The air pressure at point P is A. increasing. B. decreasing. C. constant. D. zero. 3

4 7. A wave is travelling through a medium. The diagram shows the variation with time t of the displacement d of a particle of the medium from t = to t = 25 ms d/cm t/ms Which of the following correctly gives the frequency and the amplitude of the wave? frequency / Hz amplitude / cm A B C D The diagram below shows a transverse wave on a string. The wave is moving from right to left. X Y upwards direction of wave left right downwards In the position shown, point X has zero displacement and point Y is at a position of maximum displacement. Which one of the following gives the subsequent direction of motion of point X and of point Y? Point X Point Y A. left left B. upwards upwards C. downwards left D. downwards upwards 4

5 9. A pulse is travelling along a string attached to a wall. pulse direction Which of the following shows the shape of the string after reflection from the wall? A. B. C. D. 1. A source produces water waves of frequency 1 Hz. The graph shows the variation with horizontal position of the vertical displacement of the surface of water at one instant in time. vertical displacement / cm horizontal position / cm.4 The speed of the water waves is A..2 cm s 1. B. 4. cm s 1. C. 1 cm s 1. D. 2 cm s 1. 5

6 11. The two graphs show the variation with time of the individual displacements of two waves as they pass through the same point. displacement A1 x 1 T time A 1 displacement A 2 x A 2 2 T time The displacement of the resultant wave at the point at time T is equal to A. x 1 + x 2. B. x 1 x 2. C. A 1 + A 2. D. A 1 A The diagram below shows two wave pulses moving towards one another. Which one of the following diagrams shows the resultant pulse when the two pulses are superposed? A. B. C. D. 6

7 13. When a wave crosses the boundary between two media, which one of the following properties of the wave does not change? A. Amplitude B. Wavelength C. Frequency D. Speed 14. Which of the following correctly describes the change, if any, in the speed, wavelength and frequency of a light wave as it passes from air into glass? Speed Wavelength Frequency A. decreases decreases unchanged B. decreases unchanged decreases C. unchanged increases decreases D. increases increases unchanged 15. A light wave travelling through a vacuum is incident on a block of glass. What change, if any, occurs in the frequency and amplitude of the wave as it travels into the glass? frequency amplitude A. decreases decreases B. decreases constant C. constant decreases D. constant constant 16. Waves of frequency f travel with speed c in air and enter a medium M of refractive index 1.5. Which of the following correctly gives the frequency and speed of the waves in the medium M? frequency A. f speed c 1.5 B. f 1.5c C. 1.5f c D. f 1.5 c 7

8 17. Sound waves move faster in warm air than in cold air. The diagram below shows plane waves in cold air moving towards a boundary with warm air. warm air I II III cold air boundary IV Which of the arrows shows the possible direction of waves after reaching the boundary? A. I B. II C. III D. IV 18. Light is incident on an air-glass boundary as shown below. P Q R S air glass Which one of the following is a correct statement of Snell s law? A. sin P = constant sin R B. sin P = constant sin S C. sin Q = constant sin R D. sin Q = constant sin S 8

9 19. Light travelling from water to air is incident on a boundary. Z Y X air water W Which of the following is a correct statement of Snell s law for this situation? A. sin Z = constant sin Y B. sin W = constant sin Z C. sin X = constant sin Z D. sin W = constant sin Y 2. Which of the following diagrams best shows the path of a ray of monochromatic light through a glass prism in air? A. B. glass air glass air C. D. glass air 21. The phenomenon of diffraction is associated with A. sound waves only. B. light waves only. C. water waves only. D. all waves. glass air 9

10 22. A person is walking along one side of a building and a car is driving along another side of the building. The person can hear the car approach but cannot see it. This is explained by the fact that sound waves A. travel more slowly than light waves. B. are diffracted more at the corner of the building than light waves. C. are refracted more at the corner of the building than light waves. D. are longitudinal waves. 23. A bat approaches an insect of wing span length d. The bat emits a sound wave. The bat detects the insect if the sound is reflected from the insect. d refected waves incident waves The insect will not be located if A. the insect s speed is less than the speed of the sound wave. B. the insect s wing beat frequency is greater than the frequency of the sound wave. C. the length d is much greater than the wavelength of the sound wave. D. the length d is much smaller than the wavelength of the sound wave. 1

11 24. Jeremy is walking alongside a building and is approaching a road junction. A fire engine is sounding its siren and approaching the road along which Jeremy is walking. Jeremy Fire engine Building Jeremy cannot see the fire engine but he can hear the siren. This is due mainly to A. reflection. B. refraction. C. the Doppler effect. D. diffraction. 25. Plane wavefronts are incident on a barrier as shown below. barrier Which of the following best shows the shape of the wavefronts on the other side of the barrier? A. B. C. D. 11

12 26. This question is about waves. (a) In the scale diagram below, plane wavefronts travel from medium 1 to medium 2 across the boundary AB. direction of travel medium 1 A B medium 2 State and explain in which medium the wavefronts have the greater speed (3) (b) By taking measurements from the diagram, determine the ratio speedof wave in medium1. speedof wave in medium (3) (Total 6 marks) 12

13 27. Waves on a string A travelling wave is created on a string. The graph below shows the variation with time t of the displacement y of a particular point on the string. Graph 1 y / mm t / ms 2. The variation with distance x of the displacement y of the string at t = is shown below. Graph 2 y / mm x / cm (a) Use information from the graphs to calculate, for this wave, (i) the wavelength;... (ii) the frequency;... (iii) the speed of the wave.... (b) The wave is moving from left to right and has period T. (i) On graph 1, draw a labelled line to indicate the amplitude of the wave. T (ii) On graph 2, draw the displacement of the string at t =. 4 (Total 7 marks) 13

14 28. This question is about waves and wave motion. (a) Describe, by reference to the propagation of energy, what is meant by a transverse wave. Transverse wave (b) State one example, other than a wave on a string, of a transverse wave.... A transverse wave is travelling along a string that is under tension. The diagram below shows the displacement of part of the string at time t =. The dotted line shows the position of the string when there is no wave travelling along it. displacement / cm distance along string / cm (c) On the diagram above, draw lines to identify for this wave (i) (ii) the amplitude (label this A); the wavelength (label this λ). (d) The period of the wave is s. Deduce that the speed of the wave is 25 m s

15 (e) Using the axes below, draw the displacement of the string when t = s. (The displacement of the string at t = is shown as a dotted line.) displacement / cm distance along string / cm (3) (Total 1 marks) 29. This question is about waves and wave motion. (a) (i) Define what is meant by the speed of a wave. (ii) Light is emitted from a candle flame. Explain why, in this situation, it is correct to refer to the speed of the emitted light, rather than its velocity. (b) (i) Define, by reference to wave motion, what is meant by displacement. 15

16 (ii) By reference to displacement, describe the difference between a longitudinal wave and a transverse wave. (3) The centre of an earthquake produces both longitudinal waves (P waves) and transverse waves (S waves). The graph below shows the variation with time t of the distance d moved by the two types of wave. d / km 12 P wave S wave t / s (c) Use the graph to determine the speed of (i) the P waves. (ii) the S waves. 16

17 The waves from an earthquake close to the Earth s surface are detected at three laboratories L 1, L 2 and L 3. The laboratories are at the corners of a triangle so that each is separated from the others by a distance of 9 km, as shown in the diagram below. L 9 km 1 2 L L 3 The records of the variation with time of the vibrations produced by the earthquake as detected at the three laboratories are shown below. All three records were started at the same time. L 1 L 2 start of trace L 3 time On each record, one pulse is made by the S wave and the other by the P wave. The separation of the two pulses is referred to as the S-P interval. (d) (i) On the trace produced by laboratory L 2, identify, by reference to your answers in (c), the pulse due to the P wave (label the pulse P). (ii) Using evidence from the records of the earthquake, state which laboratory was closest to the site of the earthquake. (iii) State three separate pieces of evidence for your statement in (d)(ii) (3) 17

18 (iv) The S-P intervals are 68 s, 42 s and 27 s for laboratories L 1, L 2 and L 3 respectively. Use the graph, or otherwise, to determine the distance of the earthquake from each laboratory. Explain your working. Distance from L 1 =...km Distance from L 2 =...km Distance from L 3 =...km (4) (v) Mark on the diagram a possible site of the earthquake. There is a tall building near to the site of the earthquake, as illustrated below. building ground direction of vibrations The base of the building vibrates horizontally due to the earthquake. (e) (i) On the diagram above, draw the fundamental mode of vibration of the building caused by these vibrations. 18

19 The building is of height 28 m and the mean speed of waves in the structure of the building is ms 1. (ii) Explain quantitatively why earthquake waves of frequency about 6 Hz are likely to be very destructive. 3. This question is about waves and wave properties. (3) (Total 25 marks) (a) By making reference to waves, distinguish between a ray and a wavefront (3) The diagram below shows three wavefronts incident on a boundary between medium I and medium R. Wavefront CD is shown crossing the boundary. Wavefront EF is incomplete. A C E medium I F medium R B D (b) (i) On the diagram above, draw a line to complete the wavefront EF. 19

20 (ii) Explain in which medium, I or R, the wave has the higher speed. (3) (iii) By taking appropriate measurements from the diagram, determine the ratio of the speeds of the wave travelling from medium I to medium R. The graph below shows the variation with time t of the velocity v of one particle of the medium through which the wave is travelling v / ms (c) (i) Explain how it can be deduced from the graph that the particle is oscillating. t / ms (ii) Determine the frequency of oscillation of the particle. 2

21 (iii) Mark on the graph with the letter M one time at which the particle is at maximum displacement. (iv) Estimate the area between the curve and the x-axis from the time t = to the time t = 1.5 ms. (v) Suggest what the area in c (iv) represents. (Total 17 marks) 21

22 Name: Date: Circuitry Final Review 1. Which of the following is a correct statement of Ohm s law? A. The resistance of a conductor is always constant. B. The current in a conductor is always proportional to the potential difference across the conductor. C. The resistance of a conductor increases with increasing temperature. D. The resistance of a conductor is constant only if the temperature of the conductor is constant. 2. Which of the following is a unit for electrical resistance? A. WA 2 B. AV 1 C. VW 2 s D. WV 2 3. The graph shows the variation with applied potential difference V of the current I in an electrical component. I I 1 P V 1 v Which one of the following gives the resistance of the component at point P? A. The gradient of the line at P B. The reciprocal of the gradient of the line at P C. The ratio D. The ratio I V V I

23 4. The graph shows the current-voltage (I-V) characteristic of an electrical component. I I 1 V V 1 V What is the resistance of the component at a potential difference V 1 and how does the resistance change, if at all, between potential differences V and V 1. A. B. C. D. resistance at V 1 ( V V 1 ) I 1 ( V V V I V I ) I 2 change between V and V 1 no change decreases no change decreases 5. Which graph best represents the relationship between the current I and the voltage V of a filament lamp. A. V B. V I I C. V D. V I I 2

24 6. The graph below shows the current/voltage characteristics of a filament lamp Current / 1 A Voltage / V The resistance of the filament at 4. V is A. 25 Ω. B. 4 Ω. C. 8 Ω. D. 64 Ω. 7. Three resistors P, Q and R, are each labelled 1 Ω. They are connected as shown. Q X P R Y The total resistance, when measured between points X and Y, is found to be 2 Ω. What is the correct explanation for the resistance reading? A. Resistor R is zero B. Resistor R is infinite C. Resistor P is zero D. Resistor P is infinite 3

25 8. The resistors in each of the circuits shown below each have the same resistance. circuit P circuit Q circuit S Which of the following gives the circuits in order of increasing total resistance? A. P Q S B. Q P S C. S Q P D. P S Q 9. The diagrams below show combinations X, Y and Z of three resistors, each resistor having the same resistance. combination X combination Y combination Z Which one of the following shows the resistances of the combinations in increasing order of magnitude? lowest highest A. Y X Z B. Z X Y C. X Y Z D. Z Y X 4

26 1. In the circuit below, which meter is not correctly connected? A 1 V 3 A 2 V 4 A. 1 B. 2 C. 3 D Which one of the following shows a correct circuit, using ideal voltmeters and ammeters, for measuring the I-V characteristic of a filament lamp? A. A B. A V V C. D. A V V A 5

27 12. In the circuit below, the voltmeter has a resistance 1 kω. The battery has negligible internal resistance and emf 6 V. The reading on the voltmeter is A. V. B. 2 V. C. 3 V. D. 4 V. 13. The circuit contains a battery of e.m.f. 12 V and negligible resistance. 12V 25Ω 15Ω What is the potential difference across the 25 Ω resistor? A. 3. V B. 4.5 V C. 5. V D. 7.5 V 6

28 14. In the circuit shown below, the cell has negligible internal resistance. Which of the following equations is correct? A. I 1 = 2I 2 B. I 1 = 2I 3 C. I 2 = 2I 3 D. I 3 = 2I In the circuit below, the battery has negligible internal resistance. Three identical lamps L, M and N of constant resistance are connected as shown. The filament of lamp N breaks. Which of the following shows the subsequent changes to the brightness of lamp L and lamp M? Lamp L Lamp M A. stays the same decreases B. increases stays the same C. increases decreases D. decreases increases 7

29 16. In the circuit below, resistors X, Y and Z are connected in series with a 9. V supply. +9. V 3 Ω 3 Ω X Y Z V Resistors X and Z are fixed resistors of resistance 3 Ω. The resistance of resistor Y may be varied between zero and 3 Ω. Which of the following gives the maximum range of potential difference V across the resistors X and Y? A. to 6. V B. 3. V to 6. V C. 4.5 V to 6. V D. 4.5 V to 9. V 17. In the circuit shown below, the cell has negligible internal resistance. 2R I 3 R I 1 I 2 Which of the following equations is correct? A. I 1 = 2I 2 B. I 1 = 2I 3 C. I 2 = 2I 3 D. I 3 = 2I 1 8

30 18. In which one of the circuits is it possible to vary the current in the lamp by adjusting the variable resistor? The cell has negligible internal resistance. A. B. C. D. 19. The graph below shows the variation with voltage V of the current I in three resistors X, Y and Z. I X Y Z V Which of the following corresponds to resistors for which the resistance increases with increasing current? A. X only B. Z only C. X and Z D. Y and Z 9

31 2. A battery of emf E and negligible internal resistance is connected to three resistors, each of resistance R, a voltmeter and a switch, as shown below. E R R V R The voltmeter has infinite resistance. What are the readings on the voltmeter when the switch is open and when it is closed? Switch open Switch closed A. less than ½ E B. ½ E C. ½ E less than ½ E D. ½ E ½ E 21. A battery is connected in series with a resistor R. The battery transfers 2 C of charge completely round the circuit. During this process, 2 5 J of energy is dissipated in the resistor R and 1 5 J is expended in the battery. The emf of the battery is A. 2. V. B V. C..75 V. D..5 V. 1

32 22. A metal conductor is negatively charged. It is connected to earth using a metal wire, as illustrated below. negatively-charged conductor wire earth What is the movement of charge as the conductor is earthed? A. Positive charge moves from earth to the conductor. B. Negative charge moves to earth from the conductor. C. Negative charge moves from the conductor and positive charge moves from earth. D. Positive charge from the wire moves to the conductor and negative charge moves to earth. 23. A resistor of resistance 1. Ω is connected in series with a battery. The current in the circuit is 2. A. The resistor is now replaced by a resistor of resistance of 4. Ω. The current in this circuit is 1. A. 2. A 1. A 1. Ω 4. Ω The best estimate for the internal resistance of the battery is A. 1. Ω. B. 2. Ω. C. 4. Ω. D. 5. Ω. 11

33 24. The element of an electric heater has a resistance R when in operation. What is the resistance of a second heater that has a power output three times as large at the same operating voltage? A. B. R 9 R 3 C. 3R D. 9R 25. A battery is connected to a resistor as shown below. energy transferred E B energy transferred E R The battery transfers energy E B when charge Q passes completely around the circuit and the resistor transfers energy E R. The emf of the battery is equal to E A. R. Q E B. B. Q E B + E C. R. Q EB E D. R. Q 12

34 26. The graph below shows the variation with potential difference V of the current I in an electrical component. I V V Which one of the following is a correct statement about the resistance of the component? A. For potential differences greater than V, the resistance is constant. B. For potential differences greater than V, the resistance decreases with increasing potential difference. C. The variation of current with potential difference is linear and so Ohm s law is obeyed. D. For potential differences less than V, the resistance is zero. 13

35 27. This question is about a filament lamp. (a) On the axes below, draw a sketch-graph to show the variation with potential difference V of the current I in a typical filament lamp (the I V characteristic). (Note: this is a sketch-graph; you do not need to add any values to the axes). V I (b) (i) Explain how the resistance of the filament is determined from the graph. (ii) Explain whether the graph you have sketched indicates ohmic behaviour or non-ohmic behaviour. A filament lamp operates at maximum brightness when connected to a 6. V supply. At maximum brightness, the current in the filament is 12 ma. (c) (i) Calculate the resistance of the filament when it is operating at maximum brightness. (ii) You have available a 24 V supply and a collection of resistors of a suitable power rating and with different values of resistance. Calculate the resistance of the resistor that is required to be connected in series with the supply such that the voltage across the filament lamp will be 6. V. (Total 6 marks) 14

36 28. This question is about an electric circuit A particular filament lamp is rated at 12 V, 6. ma. It just lights when the potential difference across the filament is 6. V. A student sets up an electric circuit to measure the I-V characteristics of the filament lamp. In the circuit, shown below, the student has connected the voltmeter and the ammeter into the circuit incorrectly. A 12V S V 1 kω The battery has emf 12 V and negligible internal resistance. The ammeter has negligible resistance and the resistance of the voltmeter is 1 kω. The maximum resistance of the variable resistor is 15 Ω. (a) Explain, without doing any calculations, whether there is a position of the slider S at which the lamp will be lit (3) (b) Estimate the maximum reading of the ammeter

37 (c) Complete the circuit diagram below showing the correct position of the voltmeter and of the ammeter in order to determine the I-V characteristics of the filament lamp. 12V (Total 7 marks) 29. Specific heat and a domestic shower (a) Define specific heat capacity (b) Equal masses of two different solid substances A and B are at the same temperature. The specific heat capacity of substance A is greater than the specific heat capacity of substance B. The two substances now have their temperatures raised by the same amount. Explain which substance will have the greater increase in internal energy assuming both remain in the solid phase

38 (c) The diagram below shows part of the heating circuit of a domestic shower. Cold water enters the shower unit and flows over an insulated heating element. The heating element is rated at 7.2 kw, 24 V. The water enters at a temperature of 14 C and leaves at a temperature of 4 C. The specific heat capacity of water is J kg 1 K 1. (i) Estimate the flow rate of the water (4) (ii) Suggest one reason why your answer to (c)(i) is only an estimate (Total 8 marks) 3. Electric circuits (a) The diagram below shows the circuit used to measure the current-voltage (I-V) characteristic of an electrical component X. X On the diagram above, (i) label the ammeter A and the voltmeter V. (ii) mark the position of the contact of the potentiometer that will produce a reading of zero on the voltmeter. Label this position P. 17

39 (b) The graph below shows the current-voltage (I-V) characteristics of two different conductors X and Y I / A.25 Y X V / V (i) State the value of the current for which the resistance of X is the same as the resistance of Y and determine the value of this resistance Current:... Resistance:... (ii) Describe and suggest an explanation for the I-V characteristic of conductor Y (3) (c) The two conductors X and Y are connected in series with a cell of negligible internal resistance. The current in the conductors is.2 A. Use the graph in (b) to determine (i) the resistance of Y for this value of current;

40 (ii) the emf of the cell (Total 1 marks) 31. This question is about electric circuits. (a) (i) Define emf and state Ohm s law. emf: Ohm s law: (ii) The graph below shows the I-V characteristic of a particular electrical component. V I State show the resistance of the component is determined from the graph

41 (b) In the circuit below an electrical device (load) is connected in series with a cell of emf 2.5 V and internal resistance r. The current I in the circuit is.1 A. e.m.f. = 2.5V r I =.1A load The power dissipated in the load is.23 W. Calculate (i) the total power of the cell; (ii) the resistance of the load; (iii) the internal resistance r of the cell

42 (c) A second identical cell is connected into the circuit in (b) as shown below. I =.15A load The current in this circuit is.15 A. Deduce that the load is a non-ohmic device (4) (Total 12 marks) 21

43 32. This question is about electrical components. (a) In the space below, draw a circuit diagram that could be used to determine the current-voltage (I-V) characteristics of an electrical component X. component X The graph below shows the I-V characteristics for the component X. I/A V/V The component X is now connected across the terminals of a battery of emf 6. V and negligible internal resistance. (b) Use the graph to determine (i) the current in component X; 22

44 (ii) the resistance of component X. A resistor R of constant resistance 2. Ω is now connected in series with component X as shown below. X R 2.Ω E (c) (i) On the graph in (a), draw the I-V characteristics for the resistor R. (ii) Determine the total potential difference E that must be applied across component X and across resistor R such that the current through X and R is 3. A. (d) (i) A resistor is to be used as a temperature-measuring device. List two desirable properties of such a device (ii) Explain how a temperature scale could be constructed for this resistance thermometer. (3) (Total 14 marks) 23

45 33. This question is about emf and internal resistance. A dry cell has an emf E and internal resistance r and is connected to an external circuit. There is a current I in the circuit when the potential difference across the terminals of the cell is V. V r I E (a) State expressions, in terms of E, V, r and I where appropriate, for (i) the total power supplied by the cell; (ii) the power dissipated in the cell; (iii) the power dissipated in the external circuit. (b) Use your answers to (a) to derive a relationship between V, E, I and r

46 The graph below shows the variation of V with I for the dry cell V / V I / A (c) Complete the diagram below to show the circuit that could be used to obtain the data from which the graph was plotted. 25

47 (3) (d) Use the graph, explaining your answers, to (i) determine the emf E of the cell; (ii) determine the current in the external circuit when the resistance R of the external circuit is very small; (iii) deduce that the internal resistance r of the cell is about 1.2 Ω. (3) (e) The maximum power dissipated in the external circuit occurs when the resistance of the external circuit has the same value as the internal resistance of the cell. Calculate the maximum power dissipation in the external circuit (3) (Total 18 marks) 26

48 Name: Date: Forces and Fields Final Review 1. An isolated, uncharged metal conductor is brought close to a positively charged insulator. insulating handle conductor insulator The conductor is earthed (grounded) for a short time and then the insulator is removed. Which of the following best represents the charge distribution on the surface of the conductor as a result of these actions? A. B. C. D. 2. The diagram below shows a positively charged rod brought near an isolated uncharged metal plate. rod plate As a result of bringing the rod near to the plate, A. the metal plate will gain a charge dependent on the separation of the rod and the plate. B. the metal plate will remain uncharged. C. the metal plate will gain a negative charge. D. the metal plate will gain a positive charge. 1

49 3. The diagram below shows a charged rod R suspended by insulating strings. When a stationary rod S is placed nearby, rod R is attracted towards it. rod R rod S insulated stand Consider the following statements regarding the possible nature of the rod S. I. Rod S is charged II. III. Rod S is an uncharged insulator. Rod S is an uncharged conductor. Which statement(s) can explain the attraction of rod R to rod S? A. I only B. II only C. III only D. I and III only 4. A positively charged rod is brought close to an earthed sphere S, as shown below. S The earth connection to the sphere is removed and then the charged rod is removed. The sphere S is found to be negatively charged. Which one of the following describes the material of S and the movement of charge between S and earth? Material of S Movement of charge A. conductor negative charge moves from earth to S B. insulator negative charge moves from earth to S C. conductor positive charge moves from S to earth D. insulator positive charge moves from S to earth 2

50 5. The diagram below shows two stationary point charges +2Q and Q. D C B A +2 Q Q At which point is the electric field strength greatest? A. A B. B C. C D. D 6. The diagram below shows two positive point charges of equal magnitude. A negative point charge is placed at P. P Positive charge Positive charge + + Which one of the following diagrams best shows the direction of the resultant force on the negative charge at P? A. P B. P C. P D. P

51 7. Three equal point charges X, Y and Z are fixed in the positions shown. Z q 3 1. m X 9 1. m Y q 1 q 2 The distance between q 1 and q 2 and the distance between q 2 and q 3 is 1. m. The electric force between the charges at X and Y is F. The electric force between the charges at X and Z is F A.. 2 F B.. 2 C. F. D. 2F. 8. Two positive point charges P and Q are held a certain distance apart. X P Y Q Z + + At which point(s) could the electric field strength, due to the charges, be zero? A. X only B. Y only C. Z only D. X and Z only 9. Two charges of magnitude +2Q and Q are situated as shown below. At which point is the electric field due to the two charges most likely to be zero? +2Q Q A. B. C. D. 4

52 1. Which of the following is the correct value of the electronvolt, measured in SI Units? A N B J C N D J 11. Which diagram below best represents the electric field pattern between a positively charged conducting sphere and an earthed metal plate? A. B. C. D. 12. Which one of the field patterns below could be produced by two point charges? A. B. C. D. 5

53 13. Electric field strength is defined as A. the force exerted on a test charge. B. the force per unit positive charge. C. the force per unit charge. D. the force per unit charge exerted on a positive test charge. 14. Two charged plastic balls are separated by a distance d in a vertical insulating tube, as shown. tube balls d The charge on each ball is doubled. Coulomb s law applies to the force between the balls and friction with the walls of the tube is negligible. What is now the separation of the balls? A. d 2 B. d C. 2d D. 4d 15. A proton and an alpha particle are accelerated from rest from the positively charged plate X to the negatively charged plate Y X proton alpha particle mid-point Y At the mid-point between the plates, the proton has a kinetic energy E K. At this point, the alpha particle has a kinetic energy A. E K. 2 6

54 B. E K. C. 2E K. D. 4E K. 16. An electron and a proton are accelerated from rest through potential differences of the same magnitude. After acceleration the speed of the electron is v e and the speed of the proton is v p. v p Which of the following is the best estimate for the ratio? v A. 2 B. 2 e C. D Gravitational field strength at a point may be defined as A. the force on a small mass placed at the point. B. the force per unit mass on a small mass placed at the point. C. the work done to move unit mass from infinity to the point. D. the work done per unit mass to move a small mass from infinity to the point. 18. The acceleration of free fall of a small sphere of mass kg when close to the surface of Jupiter is 25 ms 2. The gravitational field strength at the surface of Jupiter is A N kg 1. B N kg 1. C. 25 N kg 1. D N kg 1. 7

55 19. This question is about gravitation and orbital motion. (a) Define gravitational field strength at a point in a gravitational field The diagram below shows three points above a planet. The arrow represents the gravitational field strength at point A. C planet A B (b) Draw arrows to represent the gravitational field strength at point B and point C. (Total 4 marks) 2. This question is about force fields. (a) Electric fields and magnetic fields may be represented by lines of force. The diagram below shows some lines of force. A B (i) State whether the field strength at A and at B is constant, increasing or decreasing when measured in the direction from A towards B. at A:... at B:... 8

56 (ii) Explain why field lines can never touch or cross. (b) A bubble chamber is an apparatus that is used to show the paths of particles. A high-energy particle enters the chamber and, at a point P, there is a reaction that gives rise to two charged particles. The tracks of the particles are shown below. P high-energy particle There is a uniform field of force acting normally to the plane of the paper. (i) State, and explain, whether the field of force is electric or magnetic. (ii) The path of each of the two particles produced in the reaction is a spiral. One particle is spiralling clockwise, the other anti-clockwise. Suggest why they spiral in opposite directions. (iii) Outline why each path is a spiral, rather than a circle. (3) (Total 1 marks) 9

57 21. This question is about the electric field due to a charged sphere and the motion of electrons in that field. The diagram below shows an isolated, metal sphere in a vacuum that carries a negative electric charge of 9. nc. (a) (b) On the diagram draw arrows to represent the electric field pattern due to the charged sphere. The electric field strength at the surface of the sphere and at points outside the sphere can be determined by assuming that the sphere acts as though a point charge of magnitude 9. nc is situated at its centre. The radius of the sphere is m. Deduce that the magnitude of the field strength at the surface of the sphere is Vm (3) An electron is initially at rest on the surface of the sphere. (c) (i) Describe the path followed by the electron as it leaves the surface of the sphere. (ii) Calculate the initial acceleration of the electron. (3) (iii) State and explain whether the acceleration of the electron remains constant, increases or decreases as it moves away from the sphere. 1

58 (iv) At a certain point P, the speed of the electron is ms 1. Determine the potential difference between the point P and the surface of the sphere. (3) (Total 13 marks) 22. This question is about aspects of electric fields and electric charge. Fields and electric charge associated with atoms (a) Define electric field strength (b) A proton may be considered to be a point charge. For such a proton (i) sketch the electric field pattern. (ii) calculate the magnitude of the electric field strength at a distance of m from the proton. 11

59 (c) In a simple model of the hydrogen atom, an electron orbits the proton. Both electron and proton are regarded as point charges. The orbital radius of the electron is m. (i) Using your answer to (b)(ii) deduce that the magnitude of the electric force between the electron and the proton is N. (ii) Deduce that the kinetic energy of the electron is J. (3) (iii) The total energy of the electron is 14 ev. Determine the potential energy of the electron in electron volt. (3) Fields and electric charge in conductors (d) Describe the concept of drift velocity as applied to the conduction electrons in a conductor (4) 12

60 (e) Define electromotive force (e.m.f.) (f) A filament lamp is operating at normal brightness. The potential difference across the lamp is 6. V. The current in the filament is.2 A. For the filament of this lamp, calculate (i) the resistance. (ii) the power dissipated. (g) The lamp in (f) is connected in the circuit below. The lamp is still operating at normal brightness. B R The battery B has an internal resistance of 5. Ω and the resistance R of the resistor is 15 Ω. (i) Calculate the current in the resistor R. 13

61 (ii) Determine the e.m.f. of the battery. 23. This question is about gravitational fields. (4) (Total 25 marks) (a) Define gravitational field strength The gravitational field strength at the surface of Jupiter is 25 N kg 1 and the radius of Jupiter is m. (b) (i) Derive an expression for the gravitational field strength at the surface of a planet in terms of its mass M, its radius R and the gravitational constant G. (ii) Use your expression in (b)(i) above to estimate the mass of Jupiter. (Total 6 marks) 14