M13/4/PHYSI/SPM/ENG/TZ1/XX - PowerPoint Presentation

M13/4/PHYSI/SPM/ENG/TZ1/XX PhysicsStandard levelPaper 1 Monday 6 May 2013 (morning) 45 minutes

1. The mass of an elephant is 10 4 kg. The mass of a mouse is 10–2 kg. What is the ratio mass of the elephant? ? A. 10–8B. 10–6C. 106 D. 108   2. An archer aims five arrows at the centre of a target. The arrows strike the target as shown below. Which of the following describes the aim of the archer?A. Accurate and preciseB. Accurate but not preciseC. Precise but not accurate D. Neither accurate nor precise C C M13/TZ1

3HL. Which of the following is always true for an object moving in a straight line at constant speed?No forces act on the object.No resultant force acts on the object.The momentum of the object is zero.No work is being done on the object. B Translational equilibrium (1. Newton’s law)

3. The graph below shows how velocity v varies with time t for a ball thrown vertically upwards from the Earth’s surface. The shaded area is equal to theA. displacement.B. final velocity.C. change in velocity. D. acceleration. 4. Two identical balls are dropped from a tall building, one a few seconds after the other. Air resistance is not negligible. As the balls fall, the distance between the balls willA. decrease.B. increase.C. increase then remain constant.D. remain constant.ACNo air resistance y = 5 t2 when a = 0y = v tv is terminal speedtimedistance1 s 5 m2 s 20 m3 s 45 m4 s80 m M13/TZ1

4HL. Object A of mass m is lifted through a height h. Object B of mass 2m is lifted through a height 4h. The gravitational field (g) is constant over the height interval. What is the ratio Work against gravitational field is stored as gravitational potential energy ( mgh )B = (2m)g(4h) = 8mgh = 8(mgh)A D

5. Which of the following is always true for an object moving in a straight line at constant speed? A. No forces act on the object. B. No resultant force acts on the object. C. The momentum of the object is zero. D. No work is being done on the object.6. A person of weight 600 N is standing on a weighing scale in a lift (elevator). The lift is accelerating upwards at 1.0 m s–2. Which of the following is the reading on the scale?A. 0 NB. 540 NC. 600 ND. 660 Nmoving in a straight line at constant speed constant velocity Translational equilibrium: is const.   B Fnet = ma F n – 600 = 60 F n = 660 N D M13/TZ1

7. A spaceship is moving at constant speed in outer space. An internal explosion causes it to break into two pieces that move in opposite directions. Which of the following best describes what happens to its total momentum and total kinetic energy as a result of the explosion? Total momentum Total kinetic energyA.unchanged unchanged B.unchanged increasedC.increased unchanged D.increasedincreasedMomentum is conserved as the system is isolated. Kinetic energy obviously increases as the result of internal explosion. B M13/TZ1

8. A horizontal disc is rotating about a vertical axis through its centre. Points P and Q on the disc are at distances R and 2R respectively from the centre . The acceleration at P is a. Which of the following is the acceleration at Q? A. 0.5a B. a C. 2a D. 4aC   9. 4.0 kg of water at 100 °C is mixed with 1.0 kg of water at 0 °C in a container insulated from the surroundings. Which of the following is the final temperature of the water? A. 20 °C B. 25 °C C. 75 °C D. 80 °C D m 1 c 1 (100 – T) = m 2 c 2 (T – 0) c 1 = c 2 4.0 (100 – T) = 1.0 T ⟹ 400 – 4 T = T Thermal energy given by hot water = thermal energy received by cold water M13/TZ1

22HL. A ball of mass m is thrown horizontally from a cliff with initial velocity u. Air resistance is negligible. A change in which of the following will affect the horizontal distance travelled?m onlyu onlyboth m and uneither m nor u B

10. Which of the following best describes the evaporation of a liquid? Location of process Temperature at which process can occurA. at surface at any temperature of liquid B.at surface at maximum liquid temperature onlyC.throughout liquid at any temperature of liquidD.throughout liquid at maximum liquid temperature only A11. Which of the following is the temperature of an object related to? A. The kinetic energy of the object B. The random kinetic energy of the particles in the object C. The potential energy of the particles in the object D. The sum of the random kinetic energy and potential energy of the particles in the object B M13/TZ1

12. The acceleration of an object executing simple harmonic motion is proportional to the A. displacement of the object from equilibrium. B. velocity of the object. C. amplitude of oscillation. D. frequency of oscillation. A   13. A system, consisting of a mass M connected to a spring, oscillates on a frictionless surface with simple harmonic motion between two points, X and Y. Point O is the centre of the oscillation.For the system, at which of the following points is the elastic potential energy equal to thekinetic energy?A. O onlyB. X and Y only C. O, X and YD. Neither O, X nor Y D v = ± ω (x 0 2 – x 2 ) 1/2 → Simple Harmonic Motion is periodic motion in which the acceleration/ restoring force is proportional to and in opposite direction of the displacement. M13/TZ1

14. Microwave ovens cause the water molecules in food to resonate. Water molecules have a natural frequency of vibration f . In order to heat the food most effectively, the frequency of the microwaves should have a value A. less than f . B. equal to f . C. greater than f . D. as large as possible. B Natural frequency is the frequency an object will vibrate with after an external disturbance. resonance: The increase in amplitude of oscillation of a system exposed to a periodic driving force with a frequency equal to the natural frequency of the system. If the frequency of a driving force matches the natural frequency of the system, this leads to a better absorption of energy by the system, resulting in large amplitude oscillations.M13/TZ1

12HL. A point source of sound is placed behind a soundproof barrier as shown in the diagram. From where Euan is standing he can hear the sound. Which of the following best explains this observation?DiffractionInterference PolarizationRefraction A

13HL. A standing wave of frequency f is established in air in a pipe open at one end, as shown. Which of the following is the frequency of the next highest harmonic? D 1. harmonic:   3. harmonic:   5. harmonic:   Closed end + open end has only odd harmonics

17HL. Unpolarized light of intensity I 0 is transmitted through a polarizer which has a transmission axis at an angle θ to the vertical. The light is then incident on a second polarizer with a transmission axis at an angle to the transmission axis of the first polarizer, as shown below.   The intensity of the light that emerges from the second polarizer is I. What is the ratio I/I00.250.5cos2 (θ +φ )0.5cos2 φcos2θ cos2φCThe light incident on the first polarizer is unpolarized, so the angle is irrelevant – the intensity is reduced by a factor of 2.Intensity after second polarizer is given by Malus law:Intensity before*cos2 φ

15. Gas particles are equally spaced along a straight line. A sound wave passes through the gas. The positions of the gas particles at one instant are shown below. Which of the distances shown is equal to the wavelength of the wave? B Wavelength λ: the distance, measured in the direction of propagation of a wave, between two successive points with the same phase of oscillation.16. A particle with positive charge +q moves freely from one plate held at potential V1 to another plate held at potential V2. Which of the following is the electric potential energy lost by the charge? A. qV1 B. qV2 C. q (V1 +V2 ) D. q (V1 – V 2 ) D   M13/TZ1

17. Which of the following graphs shows the relationship between current I and voltage V for a filament lamp?D Filament does not obey Ohm’s law because ratio voltage to current is not constant. We say tungsten is “non-ohmic” It’s resistance increases as current through it increases, because temperature increases. by definition   M13/TZ1

18. A cell of negligible internal resistance is connected to three identical lamps. A voltmeter is connected across one of the lamps. If the filament in lamp X breaks, the reading on the voltmeter willA. become zero.B. decrease.C. stay the same.D. increase. B V = IR R doesn’t changeCurrent in the circuit flowing through resistor will be smaller if X breaks, because resistance of the parallel connection will increase, so will total resistance of the circuit, what results in smaller current. M13/TZ1

19. The gravitational field strength at the surface of a certain planet is g. Which of the following is the gravitational field strength at the surface of a planet with twice the radius and twice the mass? A. B. g C. 2g D. 4g AForce between planet (mass M) and object of mass m is weight of that object. So R – distance between center of the planet and object m = radius of the planet.   M13/TZ1

20. Two point charges of size +2q and –q are placed as shown below. In which of the regions I, II and III can the resultant electric field strength be zero?A. I only B. II onlyC. III onlyD. I and III only C In region I electric field due to (+2q) is to the left and electric field due to (–q) is to the right, but one due to (+2q) is always greater then the other one. In region II both electric fields are to the right In region III electric field due to (+2q) is to the right and electric field due to (–q) is to the left, and there is the point at which the are equal in magnitude but in opposite direction resulting in zero resultant electric field.M13/TZ1

. 21. A wire is placed in a magnetic field which is directed to the right. The wire carries a current directed into the page. Which of the following is the direction of the force on the wire? D R-H-R 1: The direction of the magnetic force on a charge/current is given by the right-hand rule 1Outstretch fingers in the direction of v (or current I).Curl fingers as if rotating vector v ( I ) into vector B.Magnetic force on a positive charge (or I) is in the direction of the thumbMagnetic force on a negative charge points in opposite direction . M13/TZ1

22. Which of the following would decrease the initial activity of a sample of plutonium? A. Placing the sample in a lead container B. Placing the sample in a dark room C. Decreasing the mass of the sample D. Decreasing the temperature of the sampleC M13/TZ1

23. A radioactive sample of initial activity 12 Bq has a half-life of 3 days. What is the activity after 6 days? A. 2 Bq B. 3 Bq C. 4 Bq D. 6 Bq B After 3 days activity is half of the initial one = 6 BqAfter next 3 days activity is half of that one = 3 Bq24. The reaction is an example of A. alpha decay. B. artificial transmutation. C. nuclear fusion. D. proton decay.BM13/TZ1

32HL. A radioactive sample of initial activity 12.0 Bq has a half-life of 3.0 days. Which of the following is the activity after 4.0 days? 3.0 Bq3.8 Bq4.0 Bq 4.8 Bq D As you are not allowed to have calculator on this exam:After 3 days activity is 6.0 BqAfter 6 days activity is 3.0 BqIf activity was linear, it would be day 4: 5.0 Bq day 5: 4.0 Bq day 6: 3.0. BqBut it is exponential So, it has to be 4.8 Bq

25. The diagram below shows an energy flow diagram (Sankey diagram) for a car. What is the efficiency of the car?A. 30 %B. 40 %C. 70 %D. 100 % A   M13/TZ1

26. A small biofuel power station burns ethanol with an overall efficiency of 25 %. The energy density of ethanol is 30 MJ kg–1. The mass of fuel consumed every second is 50 kg. Which of the following gives the useful power output in MW?   A     M13/TZ1

27. An oscillating water column ocean-wave energy converter produces power P from waves of a certain amplitude and wavespeed. Which of the following would be the power produced from waves of twice the amplitude and twice the wavespeed?A. 2PB. 4 PC. 8PD. 16P C Wave power: P/L amplitude of the wave A, length of wavefront L,  - density of water M13/TZ1 Not in the curriculum any more

D 35HL. In a nuclear fission reactor, the role of the moderator is toabsorb neutrons to shut down the reactor. speed neutrons up to increase the rate of energy production. slow neutrons down to decrease the rate of energy production. slow neutrons down to make a chain reaction more likely.

28. The total power radiated by the Sun is P. The distance from the Sun to the Earth is d. The albedo of the Earth is α . What is the power absorbed by each square metre of the Earth’s surface?DIntensity scattered = (total incident intensity)   Intensity absorbed = total incident intensity – Intensity scattered = total incident intensity – (total incident intensity )           M13/TZ1

29. Carbon dioxide is a greenhouse gas because A. it absorbs infrared light radiated by the Sun.B. it absorbs ultraviolet light radiated by the Earth.C. its natural frequency molecular oscillation lies in the infrared region.D. its natural frequency molecular oscillation lies in the ultraviolet region. C Short wavelength radiation is received from the sun and causes the surface of the Earth to warm up. The Earth will emit infra-red radiation (longer wavelengths than the radiation coming from the sun because the Earth is cooler than the sun). Some of this infra-red radiation is absorbed by gases in the atmosphere and re-radiated in all directions. Temperature of the Earth’s surface will be constant if the rate at which it radiates energy equals the rate at which it absorbs energy. The greenhouse effect is the warming of a planet due its atmosphere allowing in ultraviolet radiation from the Sun, but trapping the infrared radiation emitted by the warm Earth. The greenhouse gas has natural frequency of molecular oscillations in the infrared region, so they easily absorb energy in that region.When the frequency of the electric field is near to the natural frequency of an oscillation of the molecule, the amplitude will be high: The molecule absorbed energy from the field. Infrared radiation drives the vibration of the atoms; visible and UV radiation excites the electron cloud. The greenhouse gases like CO2 or several organic gases have natural vibration frequency in the infrared domain. They absorb it very strongly. On the other hand, they are transparent for visible and UV light. So the visible and UV light arrives to the surface of the Earth, and is absorbed by metals, rocks, soil, and the leaves of the vegetation and also by waters. The molecules can re-radiate the absorbed energy, but it is more probable, that they collide with other molecules and excite vibrations. These vibrations emit infrared photons which can not go through the atmosphere, as the greenhouse gases absorb them.M13/TZ1

30. Which of the following is most likely to increase the rate of global warming? A. DeforestationB. Increasing the use of nuclear power stationsC. Increasing the use of renewable energy sourcesD. Using natural gas instead of coal for electricity generation A M13/TZ1

M13/4/PHYSI/SPM/ENG/TZ2/XX PhysicsStandard level Paper 1 Monday 6 May 2013 (afternoon) 45 minutes

The length of the side of a cube is 10.0 ±0.3 cm. What is the uncertainty in the volume of the cube? A. ±0.027 cm3B. ±2.7 cm3C. ±9.0 cm3D. ±90 cm3     D 2. Which of the following lists three vector quantities ?A. momentum, electric field strength, displacementB. momentum, displacement, pressureC. pressure, electric current, displacementD. electric current, electric field strength, impulse A electric field strength is not a magnitudeIt is the whole vector M13/TZ2

2HL. Which of the following is necessary for an object to be in translational equilibrium? The object must be stationary.The object must move with a constant speed.The resultant force acting on the object must be zero.No forces must act on the object. C

3. An object, initially at rest, travels a distance d in a time t at a constant acceleration. What is the time taken for the object to travel 16d from rest at the same acceleration?A. 16tB. 8tC. 4tD. 2t C   4. An object is released above the surface of Earth. Which of the following correctly describes the speed and acceleration before it reaches terminal speed? Speed AccelerationA. increases remains constantB. increases decreasesC. remains constant remains constant D. remains constant decreases BAir resistance provides a drag force to objects in free fall. ▪ The drag force increases as the speed of the falling object increases resulting in decreasing downward acceleration ▪ Although acceleration decreases, the speed still increases ▪ When the drag force reaches the magnitude of the gravitational force, the falling object will stop accelerating and fall at a constant velocity. This is called the terminal velocity/speed. M13/TZ2

5. An object of mass m is connected via a frictionless pulley to an object of mass M, where M > m. M rests on a horizontal frictionless surface . What is the acceleration of the system? A   T = Ma mg - T = mamg - Ma = maa(M+m)=mg M13/TZ2

6. The graph shows the variation with distance x of the magnitude of the net force F acting on a body initially at rest. Which of the following describes how the kinetic energy and the acceleration of the body change with distance? Kinetic energy AccelerationA. decrease decreaseB. decrease increase C. increase decreaseD. increase increaseC1. ∆ KE = W net work done on an object will result in the change of kinetic energy(work is the area under the graph F vs. x)2. As net F decreases, so does acceleration M13/TZ2

7. A ball of mass 0.40 kg travels horizontally and strikes a vertical wall with a speed of 5.0 m s–1 . It rebounds horizontally with a speed of 3.0 m s–1. The ball is in contact with the wall for a time of 0.20 s.What is the average magnitude of the force exerted by the ball on the wall? A. 0.16 NB. 0.64 NC. 4 ND. 16 N D F ∆t = ∆ p = pfinal – pinitial = m(vfinal – vinitial) ▪ we can choose coordinate system (vectors !!!) positive left or positive right▪ as the force is positive we want final direction to be positive, so we choose left to be positive▪ Then F (0.2) = 0.40 [3.0 – (–5.0)] = 3.2 ▪ F = 3.2/0.2 = 16 N (positive means to the left) M13/TZ2

A car on a road follows a horizontal circular path at constant speed. Which of the following correctly identifies the origin and the direction of the net force on the car? Origin DirectionA. car engine toward centre of circleB. car engine away from centre of circleC. friction between car tyres and road away from centre of circle D. friction between car tyres and road toward centre of circleDWhatever the object, if it moves in a circle, there is some force acting upon it to cause it to deviate from its straight-line path, accelerate inwards and move along a circular path.Newton’s first law of motion – the law of inertia ... objects in motion tend to stay in motion with the same speed and the same direction unless acted upon by a net force.For object's moving in circular motion, there is a net force acting towards the center which causes the object to seek the center.M13/TZ2

7HL. An object is thrown horizontally from the edge of a high crater on the Moon. The Moon has no atmosphere. Which of the following describes the changes, if any, to the horizontal and vertical components of the velocity of the object? A HORIZONTAL MOTION VERTICAL MOTION HORIZONTAL MOTION VERTICAL MOTION

9. The temperature of an object is −153°C. Its temperature is raised to 273°C. What is the temperature change of the object?A. 699 KB. 426 KC. 153 KD. 120 KB M13/TZ2

10. Two ideal gases X and Y are at the same temperature. The mass of the molecules of gas X is twice the mass of the molecules of gas Y. Microscopic level: (absolute) temperature directly proportional to the average kinetic energy of the molecules of a substance:  k is Boltzmann constant       B M13/TZ2

11. A sample contains 4 g of helium and 20 g of neon. The mass number of helium is 4 and the mass number of neon is 20. What is the ratio ? A. 0.2B. 1C. 5D. 80 BAvogadro’s number:Number of constituent particles (atoms/molecules) per mole of a given substance is 6.022×1023 mol−1M13/TZ2

12. Which graph shows how velocity v varies with displacement x of a system moving with simple harmonic motion? A Dependence on t: v = –  x0 sin ωt = – v0 sin ωt Be aware:Dependence on x:v = at x = x0 & x = – x0 v = 0at x = 0 v = x0D. Is tempting. but D. is sinusoidal, it would show dependence on time not x.  M13/TZ2

13. An object undergoes simple harmonic motion with time period T and amplitude 0.5 m . At time t = 0 s the displacement of the object is a maximum. What is the displacement of the object at time t = ?A. − 0.50 mB. 0.50 m C. 0.25 m D. 0 m DEvery oscillator covers distance of one amplitude M13/TZ2

14. Light of wavelength 600 nm travels from air to glass at normal incidence. The refractive index of the glass is 1.5. The speed of light in air is c. Which of the following correctly identifies the speed of the waves and their wavelength in the glass?         D M13/TZ2

15. Which of the following correctly describes the direction of a ray drawn relative to a wavefront for longitudinal and transverse waves? Longitudinal wave Transverse waveA. parallel parallelB. parallel perpendicular C. perpendicular parallelD. perpendicular perpendicular D M13/TZ2

16HL. The air in a pipe, of length L and open at both ends, vibrates with a fundamental frequency f. What is the fundamental frequency of a pipe of length 1.5L and closed at one end? A    

18HL. Unpolarized light of intensity is incident on a polarizer with a vertical transmission axis. The transmitted light is incident on a sheet of material X. After transmission through X the intensity of the light is .   It is suggested that X could bea polarizer with vertical transmission axisa polarizer with horizontal transmission axisnon polarizing glass.Which of the above suggestions is/are correct?I and III onlyI onlyII onlyII and III onlyAUnpolarized light with intensity after passing through polarizer has intensity As intensity does not change after passing through second polarizer, it can be only I or III. 

    C M13/TZ2

    B M13/TZ2

18. A proton is accelerated from rest through a potential difference of 1000 V. What is the potential difference through which an alpha particle must be accelerated to gain the same kinetic energy as the accelerated proton?A. 4000 VB. 2000 VC. 500 V D. 250 V   C   19. The magnitude of the gravitational field strength at the surface of a planet of mass M andradius R is g. What is the magnitude of the gravitational field strength at the surface of a planetof mass 2M and radius 2R? A. B. C. g D. 2g  Force between planet (mass M) and object of mass m is weight of that object. So R – distance between center of the planet and object m = radius of the planet.   B M13/TZ2

20. Three positive point charges +Q are fixed in position at the vertices of an isosceles triangle. P is the mid point between two of the charges.Which arrow correctly identifies the direction of the electric field at point P?A. WB. XC. YD. Z B The only electric field that survives at point P is the one due to charge at the right angle corner. The other two cancel each other out. M13/TZ2

21HL. The diagram shows the electric field pattern due to two point charges X and Y. Y is a negative charge. Which of the following correctly identifies the charge X and the direction of the electric field? B Electric field points from negative charge toward positive. Points in the direction in which positive test charge would accelerate if placed there.

21. Three wires, P, Q and R, carry equal currents directed into the plane of the paper. Which arrow correctly identifies the direction of the magnetic force on wire P?A. W B. XC. YD. Z Currents in same direction attract!Currents in opposite direction repel!B M13/TZ2

25HL. The electric potential is VR at a point R in an electric field and at another point S the electric potential is VS . Which of the following is the work done by the electric field on a point charge +q as it moves from R to S?B A. VR − VS B. q(VR − VS)C. VS − VRD. q(VS − VR)W=q∆VElectric field would push positive charge from higher to lower potential. Therefore q(VR − VS) is positive work done by field on charge. That work is converted into kinetic energy.

22. Which particle is acted on by both the strong nuclear force and the Coulomb force?A. AntineutrinoB. Electron C. NeutronD. ProtonD 23. A nucleus of californium (Cf) contains 98 protons and 154 neutrons. Which of the following correctly identifies this nucleus of californium? C

29HL. Which of the following provides evidence for the existence of isotopes? Measurements of nuclear massesAlpha particle scatteringRadioactive decayAtomic line spectra A 32HL. A pure sample of an unknown radioactive nuclide has a very long half-life. For the sample the following quantities are knownthe number of nuclei in the samplethe mass of the samplethe activity of the sample.Which of the following will enable the half-life of the nuclide to be determined?III onlyII and III onlyI and III onlyII onlyCHalf – life T 1 /2 is the interval of time required for one-half of the atomic nuclei of a radioactive sample to decay.Activity ( becquerel - Bq) of a radioactive sample is the average number of disintegrations per second.

33HL. A nucleus of plutonium-239 can be produced from a nucleus of uranium-238 by a process which is initiated by beta capture.alpha capture.neutron capture. neutrino capture. C Number of neutrons increases

24. Which of the following gives the particles of the same energy in an increasing order of ionizing ability? A. β, α, γB. α, β, γC. γ, α, βD. γ, β, αD 25. The use of which energy source enhances the greenhouse effect the most?A. Wood B. Coal C. WindD. TidalBM13/TZ2

26. The volume expansion coefficient of water is γ . The average depth of the ocean is h. What is the expected fractional increase in the sea level for a temperature increase of Δθ ? A. γ Δθ hB. γ ΔθC. D.  B γ-coefficient of volume expansion increase in temp. coefficient of volume expansion = change in volume per unit volume per degree   M13/TZ2

27. Which of the following correctly describes the energy transformation within photovoltaic cells and within solar heating panels? Photovoltaic cells Solar heating panelsA. solar to thermal solar to electricalB. solar to thermal solar to thermalC. solar to electrical solar to electricalD. solar to electrical solar to thermal D M13/TZ2

28. An oscillating water column (OWC) ocean-wave converter produces a power P. What is the power output of this converter if the amplitude and speed of the waves are both doubled?A. 2PB. 4PC. 8PD. 16P Wave power: P/L A - amplitude of the wave, L - length of wavefront  - density of water CM13/TZ2 Not anymore in IB curriculum

29. The graph shows the spectrum of a black-body. Which graph shows the spectrum of a body of emissivity 0.5 at the same temperature as the black-body? (The original graph is shown dotted.) C M13/TZ2

35HL. Which of the following correctly describes the energy transformation within photovoltaic cells and within solar heating panels? D

30. A student states that the following factors may lead to global warmingI. decreased albedo of the Earth’s surfaceII. increase in volcanic activity III. deforestation.Which of the above statements are correct?A. I and II onlyB. II and III onlyC. I and III onlyD. I, II and III D M13/TZ2

N13/4/PHYSI/SPM/ENG/NOV/XX PhysicsStandard level Paper 1 45 minutes Wednesday 6 November 2013 (morning)

1. The sides of a square are measured to be 5.0 ± 0.2 cm. Which of the following gives the area of the square and its uncertainty?A. 25.0 ± 0.2 cm2B. 25.0 ± 0.4 cm2C. 25 ± 2 cm2D. 25 ± 4 cm2 C   =2 Uncertainties are rounded to one digit     2. Which of the following lists two vector quantities and one scalar quantity? A. force, mass, time B. acceleration, energy, momentum C. distance, impulse, power D. density, pressure, temperature B N13/NOV

2HL. Two identical balls are dropped at the same time. Ball A is dropped from a height h and ball B from a height 2h. Air resistance is negligible. B    

3. A tennis ball is dropped from the top of a high building. Air resistance cannot be neglected. Which graph represents the variation with time t of the magnitude of the acceleration a of the ball before it hits the ground?B

21HL. A ball is thrown from the top of a cliff. The initial magnitude of the velocity of the ball at time t =0 is V. The ball hits the sea at time t = T. Air resistance is negligible. Which graph shows how the vertical component of the velocity v of the ball varies with t as it falls to the sea? D v = u + gtupward positive:v=u-9.8t

Terminal speed – When air resistance is taken into account object in free fall will not accelerate forever. Air resistance depends on the speed of the object. As speed increases, so does air resistance until it reaches the value equal to the weight of the object. At that time net force is zero, so is acceleration. The speed doesn’t change any more. It is constant speed. N13/NOV

4. A model plane flies with constant velocity at constant height. Which diagram represents the forces acting on the plane? D Object is in translational equilibrium if velocity is const.

5. The net force on a body is F. The impulse of F is equal to theA. change in momentum of the body.B. rate of change of momentum of the body. C. change of kinetic energy of the body.D. change of total energy of the body.A Newton’s second law: : Impulse is defined as the product of the net force acting on an object and time interval of action: FΔt vector! (Ns) Impulse F∆t acting on an object will produce the change of its momentum Δp: F∆t = ∆p Δp = mv - mu Ns = kg m/s

6. In an inelastic collisionA. momentum and kinetic energy are both conserved.B. momentum is conserved but kinetic energy is not. C. kinetic energy is conserved but momentum is not.D. neither momentum nor kinetic energy are conserved.B

7. A force which increases uniformly from 0 to a maximum value of F is applied to an object. The object does not move until the force exceeds 0.5F. As the force increases from 0.5F to F the object moves a distance x in the direction of the force. What is the work done by this force?A. 0.25FxB. 0.5FxC. 0.75FxD. Fx C distance Work is the area under F vs distance graphforceF0.5 F x

8. A body moves with uniform speed around a circle of radius r. The period of the motion is T. What is the speed of the body?A Average velocity is zero, because displacement is zero Speed is constant and is equal to circumference/period 

9. Molar mass is defined asA. the number of particles in one mole of a substance.B. 1/12 the mass of one atom of carbon-12.C. the mass of one mole of a substance.D. the number of particles in 1/12 of a mole of carbon-12.C 10. Which of the following is true about boiling and evaporation? Boiling Evaporation A. occurs throughout liquid occurs at liquid surfaceB. occurs throughout liquid occurs throughout liquidC. occurs at liquid surface occurs at liquid surfaceD. occurs at liquid surface occurs throughout liquidAN13/NOV

11. A solid of mass m is initially at temperature ΔT below its melting point. The solid has specific heat capacity c and specific latent heat of fusion L. How much thermal energy must be transferred to the solid in order to melt it completely?A. mL + mcB. mc + mLΔTC. mcΔT + LΔTD. mcΔT + mL D To bring solid to melting point Q = mc∆T is needed.And then Q = mL is needed to melt it

12. For a body undergoing simple harmonic motion the velocity and acceleration areA. always in the same direction.B. always in opposite directions. C. in the same direction for a quarter of the period.D. in the same direction for half the period.D

13HL. The diagrams show four different organ pipes drawn to scale. Standing waves in the fundamental (firs harmonic) mode are set up inside each pipe. Which pipe produces a fundamental note with the lowest frequency? C            

13. Which graph of displacement x against time t represents the motion of a critically damped body? A Critical/heavy damping : occurs if the resistive force is so big that the system returns to its equilibrium position without passing through it. The mass comes to rest at its equilibrium position without oscillating. The friction forces acting are such that they prevent oscillations.No more in cirruculum

14. Which of the following correctly relates the direction of oscillation of the particles in a medium to the direction of energy propagation for transverse and longitudinal waves? Transverse wave Longitudinal waveA. perpendicular perpendicularB. perpendicular parallelC. parallel perpendicular D. parallel parallel B

16. Two identical waves of wavelength λ leave two sources in phase. The waves meet and superpose after travelling different distances. Which path difference will result in destructive interference?B 15. Which of the following relates the amplitude A of a travelling wave to the intensity I ?A ∝ I−1A ∝ I−1/2A ∝ I1/2A ∝ I2I ∝ A2C

Through which angle should polarizer 2 be rotated so that no light is transmitted?450 600900 1800 16HL. Two polarizing filter are set up so the transmitted light is at a maximum intensity. C

17. A resistor X of resistance R is made of wire of length L and cross-sectional area A. Resistor Y is made of the same material but has a length 4L and a cross-sectional area 2A. X and Y are connected in series. What is the total resistance of the combination? A. 1.5RB. 2RC. 3RD. 9R C  N13/NOV

18. A light dependent resistor L is connected in series with a cell C and a fixed resistor R. The cell has a negligible internal resistance. V OUT is the output voltage across L.Which change will increase VOUT?A. Connect another resistor in parallel with L B. Decrease the intensity of light on L C. Increase the resistance of RD. Decrease the emf of CBA photoresistor or light-dependent resistor (LDR) or photocell is a light-controlled variable resistor. The resistance of a photoresistor decreases with increasing incident light intensity; in other words, it exhibits photoconductivity. A photoresistor can be applied in light-sensitive detector circuits, and light- and dark-activated switching circuits.   If intensity of light decreases, R L increases, and VOUT increases

19. Each of the resistors in the circuit has a resistance of 2.0 Ω. The cell has an emf of 3.0 V and negligible internal resistance. The ammeter has negligible resistance.What is the ammeter reading?A. 0.4 AB. 0.5 AC. 1.5 AD. 2.0 A C 1/R TOT = 1/R + 1/3R = 4/3R RTOT = 3/2 Ω I = emf/RTOT = 2 ACurrent through one resistor I1 Current through three resistors I3 2 = I1 + I3R I1 = 3R I3 I1 = 3I3 I3 = 0.5 A I1 = 1.5 AN13/NOV

20. Which diagram represents the pattern of electric field lines of two small positive point charges held at the positions shown? B

21. The force F between particles in gravitational and electric fields is related to the separation r of the particles by an equation of the form Which of the following identifies the units for the quantities a, b and c for a gravitational field? a b and cA. N m2 C–2 CB. N m2 C–2 kgC. N m2 kg–2 CD. N m2 kg–2 kg Both A and D will result in the product (abc) = N m2 , but the problem asks about gravitational force, not electric one. D N13/NOV

22. An electron of mass me and charge e accelerates between two plates separated by a distance s in a vacuum. The potential difference between the plates is V.What is the acceleration of the electron? C        

23HL. A hollow sphere of radius R is positively charged. Which graph shows how the magnitude of the electric field E varies with r? A

23. In a particular atom, the nucleon number is the total number ofA. protons.B. neutrons. C. electrons.D. protons and neutrons.24. For which quantity can the unit MeV c–2 be used?A. MassB. MomentumC. Kinetic energy D. Binding energyD A   Unit for mass is unit for energy (MeV) divided by c 2

25. Uranium-238 forms a nucleus of plutonium-239 as a result ofA. electron capture followed by alpha decay.B. electron capture followed by beta decay.C. neutron capture followed by alpha decay.D. neutron capture followed by two beta decays. D 2 protons more means 2 neutrons into 2 protons and two electrons = two beta decays :  That would leave the same number of nucleons, so one extra neutron must be capturedN13/NOV

29HL. A I think there is a mistake here. Three lines correspond to three transitions: X →1 small frequency, big λX→2 big frequency, small λ2→1 a bit bigger frequency, small λ

26. In the production of electric power, an advantage of using photovoltaic cells rather than fossil fuels is that the photovoltaic cellsA. can be effective in any location.B. can be used continuously.C. have low initial set-up costs.D. are more environmentally friendly when in use. D

27. What is the main role of the control rods and the main role of the moderator in a thermal fission reactor? Control Rods ModeratorA. decrease neutron speed decrease neutron speedB. decrease neutron speed absorb neutrons C. absorb neutrons decrease neutron speedD. absorb neutrons absorb neutrons C Main energy transformations in a nuclear power station: nuclear energy → thermal energy → mechanical energy → electrical energy Three important components in the design of all nuclear reactors are moderator, control rods and heat exchanger.▪ Moderator is a medium that slows down fast neutrons to make them suitable for reaction (water, graphite, heavy water). ▪ Control rods are movable rods that readily absorb neutrons. They can be introduced or removed from reaction chamber in order to control the rate of fission of uranium and plutonium. Made of chemical elements capable of absorbing many neutrons without fissioning themselves (cadmium, hafnium, boron, etc)▪ Heat exchanger is used to seal off the place where nuclear reactions take place from the rest of the environment. In some nuclear power plants, the steam from the reactor goes through a heat exchanger to convert another loop of water to steam, which drives the turbine. The advantage to this design is that the radioactive water/steam never contacts the turbine.

28. An oscillating water column (OWC) ocean-wave energy converter uses waves to alter the air pressure in a chamber. Which energy resources must have been involved for this method to generate electricity?I. TidesII. WindIII. SolarA. I onlyB. II only C. I and II onlyD. II and III only D It is wave not tide !!!!no more in curriculum

35HL.   B  

29. The surface temperature of a black-body emitter is doubled. By what factor does the power emitted by the body increase?A. 32B. 16C. 4D. 2   B 30. Which option is not a possible solution to reduce the enhanced greenhouse effect?A. Decommission nuclear power plantsB. Replace the use of coal and oil with natural gasC. Use combined heating and power systems (CHP)D. Use hybrid motor vehiclesA