enwaecphysics2009

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1. In which of the following states of matter do the molecules vibrate about their mean positions? Liquids only Solids only Liquids and gases only Solids, liquids and gases 2. Which of the following properties of a steel bar can be measured in terms of the dimensions of length only? Weight Density Pressure Volume 3. In a hydraulic process, a force of 40N is applied to the smaller piston of area 10cm2. If the area of the larger piston is 200cm2, calculate the force obtained. 800N 500 N 80N 50N 4. A body of volume 0.046m3is immersed in a liquid of density 980 kgm-3with □(3/4) of its volume submerged. Calculate the upthrust on the body. [g=10ms-2] 11.27N 33.81N 112.70N 338.10N 5. Which of the following types of motion will be produced when a pair of equal and opposite non-collinear parallel forces acts on a body? Vibrational motion Random motion Translational motion Rotational motion 6. A body moving in a circle at a constant speed has A velocity tangential to the circle A constant kinetic energy An acceleration directed towards the circumference of the circle Which of the following statements above are correct? I and II only II and III only I and III only I, II and III 7. A car moves with a speed of 30ms-1. Calculate the distance travelled in 30s. 30m 60m 450m 900m 8. A moving body accelerates when it Changes its direction at constant speed Maintains a constant linear speed Covers equal distances in equal times in a straight line Is acted upon by balanced forces 9. The following properties of a solid are measured on earth: I. weight II. Specific heat capacity III. Density Which of the properties will have a different value if measured in space? I only II only III only II and III only 10. Which of the following vector diagrams below represents the following vector positions?

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11. Two forces of 6N and 8N, act eastwards and northwards respectively on a body. Calculate the magnitude of their equilibrant. 2N 7N 10N 14N 12. The period of a simple pendulum of length 80.0cm was found to have doubled when the length of the pendulum was increases by X. Calculate X. 26.7cm 40.0cm 160.0cm 240.0cm 13. A body of mass 5 kg moving with a velocity of 30ms-1 due east is suddenly hit by another body and changes its velocity to 50ms-1in the same direction. Calculate the magnitude of the impulse received. 100 Ns 150 Ns 250 Ns 400 Ns 14. Electrical energy is measured in Ampere Coulomb Kilowatt-hour Kilowatt 15. A stone of mass 0.5kg is dropped from height a height of 12m. Calculate its maximum kinetic energy. [g=10ms-1] 3.0 J 6.0 J 30.0 J 60.0 J 16. A machine of efficiency 80% is used to lift a box. If the effort applied by the machine is twice the weight of the box, calculate the velocity ratio of the machine. 0.50 0.63 0.80 1.60 17. A faulty thermometer registers 102.5℃ at 100℃. If the thermometer has no zero error, what will it register at 55℃? 54.6 ℃ 55.0 ℃ 56.0 ℃ 56.4 ℃ 18. A rod of initial length 2m at a temperature of 25℃ is heated to 80℃. Calculate the increase in the length of the rod if its linear expansivity is 4.0 × 10-3K-1. 0.26 m 0.44 m 0.53 m 0.84 m 19. As a bicycle tyre was being pumped up, it was noticed that contrary to Boyle’s law the volume increased as the pressure increased. The best explanation of this is that Boyle’s law is only true for Ideal gases A fixed mass of gas A mixture of gases A gas a variable temperature 20. It takes 4 minutes to boil a quantity of water using an electrical heating coil. How long will it take to boil the same quantity of water using the same heating coil if the current is doubled? [Neglect any external heat losses] 8 minutes 4 minutes 2 minutes 1 minutes

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21. When table salt is added to ice, the melting point of the ice Is raised Is lowered Remains unchanged Is first raised, then lowered 22. Which of the following factors affect the rate of evaporation of a liquid? Exposed surface area Temperature of the surroundings Thermal capacity of the liquid Relative humidity of the surroundings II and III only II, III and IV only I, III and IV only I, II and IV only 23. Which of the following instruments is used to measure relative humidity? Hydrometer Barometer Hypsometer Hygrometer 24. The maximum displacement of a vibrating tuning fork is its Amplitude Frequency Period Wavelength 25. A boat is rocked by waves of speed 30 ms-1whose successive crests are 10m apart. Calculate the rate at which the boat receives the waves. 30 s-1 10 s-1 3 s-1 1 s-1 26. Which of the following waves is not transverse? Light waves Sound waves Sea waves Radio waves 27. Light travelling through a small pinhole usually does not make a shadow with a distinct sharp edge because of Diffraction Interference Reflection Refraction 28. The angel of incidence of a ray of light on a plane mirror is 55°. Determine the angle between the reflected ray and the mirror. 35° 45° 55° 110° 29. A concave mirror forms a magnified and erect image only when the object is placed At the centre of curvature At the focus Between the focus and the pole of the mirror Beyond the radius of curvature 30. A thin lens is placed 50 cm from an illuminated object. The image produced has linear magnification of□(1/4). Calculate the power of the lens in diopters. 2.5 D 5.0 D 10.0 D 25.0 D

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31. Which of the following characteristics of light determines its colour? Velocity Wavelength Amplitude Intensity 32. Which of the following is not part of the electromagnetic spectrum? X-rays Microwaves Infrared radiation Alpha rays 33. Sound interference is necessary to produce the phenomenon of Beats Doppler effect Acoustic resonance Echo 34. A satellite in circular motion around the earth does not have A gravitational force acting on it A uniform velocity An acceleration A centripetal force acting on it 35. When a conductor mounted on an insulating stand is charged and left for sometime, the conductor eventually loses all its charges. This is because the Electric charges evaporate from the surface of the conductor Charges are conducted to earth Charges on the conductor are neutralized by opposite charges from the surrounding air Charges ionizes the surrounding air Use the information below to answer questions 36 and 37. An isolated metal sphere of radius R, carrying an electric charge, Q, is situated in a medium of relative permittivity, εr. A test charge is placed at a point P, distance r from the surface of the sphere. Let ε0 represent the permittivity of the free space. 36. The electric potential at P is given by the expression Q/(4πε_0 ε_r ) Q/(4πε_0 ε_r (R+r)) Q/(4πε_0 ε_r (R-r)) Q/(4πε_0 ε_r R) 37. The magnitude of the electric field intensity at P is given by the expression Q/(4πε_0 ε_r r^2 ) Q/(4πε_0 ε_r (R+r)^2 ) Q/(4πε_0 ε_r (R-r)^2 ) Q/(4πε_0 ε_r R^2 ) 38. A resistor of resistance R is connected to a battery of negligible internal resistance. If a similar resistor is connected in series with it, the Effective resistance of the circuit is halved Total power dissipated is doubled Total current in the circuit is halved Terminal voltage is halved 39. A cell of e.m.f. 1.5V is connected in series with a resistor of resistance 3.0Ω. A voltmeter connected the cell registers 0.9 V. Calculate the internal resistance of the cell. 2.0 Ω 3.0 Ω 5.0 Ω 6.0 Ω 40. A wire of resistivity 4.40 ×10-5Ω cm has a cross sectional area of 7.50 × 10-4cm2. Calculate the length of this wire that will be required to make a 4.0 Ω resistor. 82.50 cm 68.18 cm 15.90 cm 11.94 cm

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41. A battery of e.m.f. 12.0V and internal resistance 0.5Ω is connected to 1.5Ω and 4.0Ω series resistors. Calculate the terminal voltage of the battery. 13.0 V 11.0 V 3.0 V 1.0 V 42. If the direction of the current in a straight wire is reversed, the magnetic field Remains the same Becomes parallel to the wire Ceases to exist Is oppositely directed 43. An ideal step-down transformer steps up Power Energy Current Voltage 44. An inductor of inductance 1.0 H is connected in series with a capacitor of capacitance 2.0μF in an a.c. circuit. Calculate the value of frequency that will make the circuit to resonate. 112.5 Hz 225.0 Hz 353.5 Hz 707.1 Hz 45. An ammeter connected to an a.c circuit records 5.5 A. The peak current in the circuit is 7.8 A 7.1 A 3.9 A 3.5 A The table below shows the energy distribution for various levels of an atom. Use it to answer questions 46and 47. Energy level (n) 1 2 3 4 Energy (eV) -13.6 -3.39 -1.51 -0.85 [h=6.6 ×10-34Js e = 1.6×10-19C c =3.0×108ms-1] 46. Calculate the first excitation energy of the atom. 1.60 × 10-19J 1.02 × 10-18J 1.60×10-18J 1.02 ×10 J 47. If the atom de-excites from n =2, the wavelength of the emitted radiation is 2.4 ×10-7m 1.2 ×10-7m 2.4×10-9m 1.2×10-9m 48. Two isotopes of uranium are designated as 238U and 235U. The numbers 238 and 235 represent their Atomic numbers Nucleon numbers Proton numbers Neutron numbers 49. The main difference between x-rays and -rays lies in their Ionizing ability Absorption rate Mode of production Mode of propagation 50. An electron of mass 9.1×10-31kg moves with a speed of 107ms-1. Calculate the wavelength of the associated wave. [h=6.6×10-34Js] 9.10×10-34m 4.55×10-17m 7.25×10-11m 6.20×10-8m

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