05-06/F. 6 Final Exam/AL Physics/Paper 1/P.1 PLK VICWOOD K.T. CHONG SIXTH FORM COLLEGE Form Six Second Term Final Examination (2005-2006) A Physics A-Level Paper 1 Question/Answer Book A Time Allowed: 3 hours This paper must be answered in English INSTRUCTIONS 1. This paper consists of TWO sections, A and B. Answer ALL questions in BOTH sections. 2. Questions for sections A and B are printed in two separate Question- Answer Books A and B respectively. 3. Sections A and B each carries 54 marks. You should spend about 1 hour 30 minutes answering each section. 4. Write your Name, Class and Class Number in the spaces provided on the covers of Question-Answer Books A and B. 5. Question-Answer Books A and B must be handed in separately at the end of the examination. 6. Supplementary answer sheets will be supplied on request. Write your Name and Class on each sheet and fasten them with string inside this book. Name Class Class No. 1 2 3 4 5 Total Marker s Use Only
05-06/F. 6 Final Exam/AL Physics/Paper 1/P.2 i. Answer ALL questions in this section. ii. Write your answers in the spaces provided in the question/answer book. In calculations you are advised to show all the main steps in your working. iii. Assume: acceleration due to gravity = 10 ms -2 Question No. 1 2 3 4 5 Marks 11 12 9 15 7 1. Two cannons are mounted as shown in Figure 1.1 and rigged to fire simultaneously. They are used in a circus act in which two clowns serve as human cannonballs. The clowns are fired toward each other and collide at a height y above the muzzles of the cannons. Clown A is launched at an angle θ A with a speed of 9.00 m/s. The horizontal separation between the clowns as they leave the cannons is 6.00 m. The time variation of the speed of clown A is shown in Figure 1.2. collision speed/ms -1 Clown A 9.00 m/s θ A y θ B v B Clown B 9.00 7.81 6.00 m 2.33 time Figure 1.1 Figure 1.2 t 1 (a) Using the graph in Figure 1.2, show that the angle θ A is 75 and the time of flight t 1 is 1.61 s. (b) Find the horizontal distance travelled by clown A at time t 1 and the height y.
05-06/F. 6 Final Exam/AL Physics/Paper 1/P.3 (c) Determine the launch speed v B and the launch angle θ B for clown B. (4 marks) (d) In Figure 1.1, sketch the paths taken by Clown A and B before collision. 2. (a) A 50 g block moving at 0.6 m/s on a frictionless horizontal surface collides with a pan of negligible mass attached to a spring of force constant 7.5 N/m as shown in Figure 2.1. 50 g 0.6 m/s Figure 2.1 (i) What is the maximum compression of the spring? (ii) How long does the block maintain in contact with the pan? (b) In Figure 2.2, another identical block is now placed on the top of the previous block. The whole system is again moving with the same speed as in part (a) towards the pan. Assume both the block and the pan have the same height. 50 g 0.6 m/s 50 g Figure 2.2
05-06/F. 6 Final Exam/AL Physics/Paper 1/P.4 (i) If there is no friction between any two surfaces, the upper block is found to slip relative to the lower block when the lower block is in contact with the pan. To what direction will the upper block slip? Explain briefly. (ii) If there is friction between the blocks, determine the minimum friction between the blocks such that the upper block does not slip relative to the lower block. (4 marks) (iii) With friction, the upper block may also topple during the motion. If the base of the block is a square of side 5 cm, what would be the maximum height of the upper block to prevent it from overturning?
05-06/F. 6 Final Exam/AL Physics/Paper 1/P.5 3. Figure 3.1 shows how the electric potential V changes along a straight line AB. The distance AB is 7.0 cm. A negatively charged particle of 2.0 C is to be released at a point 4.5 cm from A with initial kinetic energy 3.0 J and moves along AB. The mass of the charge is 6.2 10 12 kg. A 4.5 cm Charge il B 4 V/V 2 0 1 2 3 4 5 6 7 Figure 3.1 Distance from A/cm (a) If the charged particle is initially moving towards A, does it reach a turning point (if so, what is its distance from A) or does it pass over A (if so, what is its speed at A)? Explain briefly. (b) If the charged particle is initially moving towards B does it reach a turning point (if so, what is its distance from A) or does it pass over B (if so, what is its speed at B)? Explain briefly. (c) Sketch a graph showing the corresponding variation of electric field along AB in the space provided. Take the direction to the left to be positive. 4. (a)
05-06/F. 6 Final Exam/AL Physics/Paper 1/P.6 Figure 4.1 Switch S cell E, e.mf. = 12 V A 1 R 1 A 2 R 2 C + + Figure 4.1 shows a circuit in which the cell E and the ammeters have negligible resistance. The e.m.f. of E is 12 V, and the resistors R 1 and R 2 are of resistances 2 kω and 3 kω respectively. The capacitor is initially uncharged. At time t = 0, the switch S is closed and the capacitor allowed to charge fully from time t = 0 to time t = t 1. At time t = t 1, switch S is opened again. (i) Find the currents registered by ammeters A 1 and A 2 (I) at the moment the switch S is closed; (II) when the steady state is reached after closing switch S; (III) at the moment when switch S is opened again. (ii) The time variation of the potential difference across the capacitor is now investigated. (I) Suggest a suitable instrument to measure the potential difference across the capacitor. (1 mark) (II) In the space below sketch a graph to show how the potential difference across the capacitor varies with time, from time t = 0 to a time later than t 1. (b) The circuit in part (a) is modified into another circuit, as shown in Figure 4.2, in an attempt to measure the speed of a rifle bullet. A and B are two pieces of foil
05-06/F. 6 Final Exam/AL Physics/Paper 1/P.7 which the bullet breaks before embedding itself in a wooden block (not shown) placed behind B. The R-C part of the circuit is used as a clock. Figure 4.2 R 1 R 2 Bullet A B C (i) Explain what measurements you would take in order to calculate the speed of the bullet. (ii) For a bullet from a high-velocity rifle which is expected to have a speed of about 200 ms -1, suggest a suitable value for R 2 if C is a 0.47 µf capacitor and R 1 is a fixed resistor of 2.0 kω. Take the distance AB to be 0.4 m.
05-06/F. 6 Final Exam/AL Physics/Paper 1/P.8 5. In Figure 5.1 shown, two fixed resistors with resistance R 1 and R 2 are connected to a variable resistor with resistance R V and a centre-zero ammeter with internal resistance R A. The switch K is open. R V A K R 1 R 2 R A Figure 5.1 (a) The variable resistance R V is adjusted such that R V = 5R A and R A = R 1 = R 2 and the switch is then closed. Explain what would happen to the current through the battery. (b) The circuit shown may be used for determining the internal resistance of the centre-zero ammeter R A without addition of any apparatus. Assuming that the values of R 1, R 2 and R V can be known, suggest and explain clearly how you would find the value of R A. (4 marks) - End of Section A -
05-06/F. 6 Final Exam/AL Physics/Paper 1/P.9 PLK VICWOOD K.T. CHONG SIXTH FORM COLLEGE Form Six Second Term Final Examination (2005-2006) B Physics A-Level Paper 1 Question/Answer Book B Time Allowed: 3 hours This paper must be answered in English INSTRUCTIONS 1. Write your Name, Class and Class Number in the spaces provided. 2. Question-Answer Books A and B must be handed in separately at the end of the examination. 3. Supplementary answer sheets will be supplied on request. Write your Name and Class on each sheet and fasten them with string inside this book. Name Class Class No. 6 7 8 9 Total Marker s Use Only
05-06/F. 6 Final Exam/AL Physics/Paper 1/P.10 i. Answer ALL questions in this section. ii. Write your answers in the spaces provided in the question/answer book. In calculations you are advised to show all the main steps in your working. iii. Assume: acceleration due to gravity = 10 ms -2 Question No. 6 7 8 9 Marks 13 16 12 13 6. The most valued orbit for a communications satellite is a parking orbit. Unfortunately, room along a parking orbit is limited because the satellites in such an orbit cannot be too close to one another or the signal quality is degraded. The least angular separation of the circular orbit is 3.00. Given: The radius of the Earth is 6400 km (a) Explain the meaning of a parking orbit. (b) Show that the minimum separation between any two satellites along the parking orbit is 2200 km. (4 marks) (c) A 220 kg communications satellite is now set to move in the above orbit. Suppose it loses mechanical energy at the average rate of 1.4 10 5 J per orbital revolution. Adopting the reasonable approximation that the satellite s orbit becomes a circle of slowly diminishing radius, determine the satellite s altitude and speed at the end of its 1500th revolution. (5 marks)
05-06/F. 6 Final Exam/AL Physics/Paper 1/P.11 (d) Surprisingly the speed obtained in part (c) is found to be greater than its initial speed after the loss of mechanical energy. Explain why. 7. Figure 7.1 shows a horizontal conducting metal rod of length l that can slide freely on two parallel metal rails inclined at angle θ with the horizontal. The metal rails are connected with a resistor with resistance R. A uniform magnetic field B exists between the two rails pointing in a direction vertically upwards. metal rod l magnetic field B pointed vertically upwards θ metal rails Figure 7.1 θ resistor (a) Mark on Figure 7.1 the direction of induced current I flowing in the metal rod when it slides down the rails. (1 mark) (b) The rod is observed to reach a terminal speed as it slides down the rails. Explain briefly.
05-06/F. 6 Final Exam/AL Physics/Paper 1/P.12 (c) Suppose the rod has reached a terminal speed v along the metal rails as shown in Figure 7.2. metal rod B metal rail v θ Figure 7.2 (i) Using Faraday s law, show that the magnitude of induced current I is given Blv cosθ by: I = R (ii) In Figure 7.2, draw and label all the forces acting on the metal rod. (iii) From what you have drawn, show that the magnetic force acting on the rod is given by: F = mg tanθ (d) It is given that l = 10.0 cm, θ = 30, R = 0.12 Ω, B = 0.36 T and v = 4.5 ms -1. (i) Estimate the mass of the metal rod. (ii) Show also that the mechanical power input by the gravity equals to the electrical power dissipation in the resistor.
05-06/F. 6 Final Exam/AL Physics/Paper 1/P.13 8. Atoms of Neon-20 are ionized by the removal of one electron from each atom. For a Neon-20 ion, it has a mass of 3.32 10 26 kg. The ions are accelerated from rest in a vacuum through a potential difference of 1400 V. They are then injected into a region of space where there are uniform electric and magnetic fields acting at right angles to the original direction of motion of the ions, as shown in Figure 8.1. Given: charge of electron = 1.6 10 19 C Path of neon ions Region of uniform electric and magnetic fields Figure 8.1 (a) (i) On the diagram above indicate clearly the directions of the electric and magnetic fields so that the ions pass undeflected through the region. (ii) Explain why the ions go straight through the region. (1 mark) (b) Calculate the speed of the accelerated ions on entry into the region of the electric and magnetic fields. (c) The electric field strength E is 6.2 10 3 V/m. Calculate the magnitude of the magnetic field B so that the ions are not deflected in the region of the fields. (d) If the electric field is removed from the region and the magnetic field is kept unchanged. (i) What happens to the path of the ions inside the region? (1 mark)
05-06/F. 6 Final Exam/AL Physics/Paper 1/P.14 (ii) The mechanism by which the neon atoms are ionized is changed such that each atom loses two electrons. Would the path of the ions inside the region be affected? Explain. (4 marks) 9. This question is about electromagnetic induction. A coil, wrapped around an iron rod, is connected via a switch to a 12 V d.c. supply of negligible internal resistance as shown in Figure 9.1. 4.0 3.5 Primary current /A 3.0 2.5 2.0 1.5 Figure 9.1 1.0 0.5 0 0 2 4 6 8 10 12 14 16 18 20 Figure 9.2 Time /ms (a) The graph, Figure 9.2, shows how the current in the coil varies with time from the instant the switch is closed to the time when the current reaches a steady value. (i) Explain why the current cannot rise instantaneously to the final steady value. (ii) Use the information on the graph,
05-06/F. 6 Final Exam/AL Physics/Paper 1/P.15 (I) calculate the resistance of the coil; (II) find the self-inductance of the coil by considering the half-life. (iii) If the coil is replaced by another coil of doubled in number of turns wrapping evenly on the same segment of the iron rod, state and explain the effect on the initial rate of change of current and the steady current. (4 marks) (b) Figure 9.3 shows a second coil wrapped around the iron rod. This arrangement provides the high voltage pulses used to ignite the fuel in a petrol engine. Figure 9.3 A steady current through the original coil produces a flux density of 0.16 T in the iron rod. The iron rod has a cross-sectional area of 3.1 10 4 m 2. When the switch is opened the flux in the iron rod falls to zero in about 10 µs. Estimate the average voltage induced in the 6000 turn second coil as the flux falls to zero. - End of Paper -