WAEC - Physics (2007)

• 1

  Which of the following observations is not an effect of surface tension?

  回答

  (D)

  water flowing out more easily then engine oil from a container
• 2

  Which of the following physical quantities is correctly paired with it's corresponding S.I unit?

  回答

  (B)

  power[Js^-1]
• 3

  A liquid of volume 2.00 m3 and density 1.00 x 103 is mixed with 3.00 m3 of another liquid of density 8.00 x 103kg m-3. Calculate the density of the mixture [Assuming there is no chemical reaction]

  回答

  (D)

  5.20 x 10³ kg m^-3
• 4

  Which of the following statements about solid friction are correct? It i. is a force ii. occurs between the surfaces of two bodies in contact iii. depends on the area in contact

  回答

  (A)

  i and ii only
• 5

  A mass of mass m, experiences a viscous drag, F and an upthrust, U as he descends towards the ground at a steady velocity, Using a parachute. If the acceleration of free fall is g, which of the following expressions is correct?

  回答

  (B)

  U + F - mg = 0
• 6

  a body moving at a constant speed accelerates when it is in

  回答

  (C)

  circular motion
• 7

  An object of mass 2 kg moves with a uniform speed of 10ms^-1 for 5s along an straight path. Determine the magnitude of its acceleration

  回答

  (A)

  0 ms^-2
• 8

  The team rectilinear acceleration means the rate of increase of

  回答

  (D)

  velocity along a straight-line path in a unit time
• 9

  A body moving with an initial velocity U accelerates until it attains a velocity of V within a time t. The distance, s covered by the body is given by the expressions

  回答

  (C)

  s = (\(\frac{v + u}{2}\))t
• 10

  A body accelerates uniformly from rest at 2ms^-2. Calculate the magnitude of its velocity after travelling 9m

  回答

  (B)

  6.0ms^-1
• 11

  A swinging pendulum between the rest position and its maximum displacement possesses

  回答

  (D)

  both kinetic and potential energy
• 12

  A block of mass 4.0kg causes a spiral spring to extend by 0.16m from its unstretched position. The block is removed and another body of mass 0.50kg is hung from the same spiral spring. If the spring is then stretched and released, what is the angular frequency of the subsequent motion? [g = 10 ms ^-2]

  回答

  (A)

  10\(\sqrt 5\) rads^-1
• 13

  An external force of magnitude 100N acts on a particle of mass 0.15kg for 0.03s. Calculate the change in the speed of the particle

  回答

  (C)

  20ms^-1
• 14

  A car of mass 800kg moves from rest on a horizontal track and travels 60m in 20s with uniform acceleration. Assuming there were no frictional forces, calculate the accelerating force

  回答

  (A)

  240.0N
• 15

  A plane inclined at 30^o to the horizontal has an efficiency of 50%. Calculate the force parallel to the plane required to push a load of 120N uniformly upn the plane

  回答

  (B)

  120.0N
• 16

  Mechanical energy can be either

  回答

  (C)

  potential or kinetic
• 17

  Which of the following surfaces will radiate heat energy best?

  回答

  (C)

  black surface
• 18

  The ice and steam point on a mercury-in-glass thermometer are 10cm and 30cm respectively. Calculate the temperature in decree Celsius when the mercury meniscus is the 14cm mark

  回答

  (A)

  20^oC
• 19

  Which of the following statements distinguishes thermal conduction for convection? i. Conduction requires a material medium while convection does not ii. In convection, there is actual motion of hot material, while in conduction, molecules molecules vibrates faster about their mean positions iii. Conduction takes place in solids while convection takes place in fluids.

  回答

  (B)

  ii and iii only
• 20

  A cube made of metal of linear expansivity \(\alpha\) is heated through a temperature \(\theta\). If the initial volume of the cube is V_o, the correct expression for the increase in volume of the cube is

  回答

  (D)

  \(3 \alpha V_o \theta\)
• 21

  A relative density bottle of volume 50cm³ is completely filled with a liquid at 30^oC. It is then heated to 80^oC such that 0.75cm³ of the liquid is expelled. Calculate the apparent cubic expansivity of the liquid.

  回答

  (A)

  0.00030k^-1
• 22

  A body of mass 200g and specific heat capacity 0.4Jg^-1k^-1 cools from 37^oC to 31^oC. Calculate the quantity of the heat released by the body.

  回答

  (C)

  480J
• 23

  According to the kinetic theory of gasses, which of the following property of a gas can be affected by the collision of the gas molecule with the walls of the container?

  回答

  (D)

  pressure
• 24

  The pressure of a fixed mass of an ideal gas at 27°C is 3 pa. The gas is heated at a constant volume until its pressure is 5 pa. Determine the new temperature of the gas.

  回答

  (B)

  227^oC
• 25

  Which of the following wave is electromagnetic?

  回答

  (A)

  x-rays
• 26

  The distance between two points P and Q, along a wave is 0.05m. If the wave length of the wave is 0.10m, determine the phase angle between P and Q in radians

  回答

  (B)

  \(\pi\)
• 27

  Which of the following phenomena is not a direct consequence of rectilinear propagation of light?

  回答

  (C)

  diffraction of light
• 28

  An object is placed 10cm in front of a plane mirror. If it is moved 8cm away father away from the mirror, determine the distance of the final image from the mirror

  回答

  (D)

  18cm
• 29

  In which of the following piece of apparatus is the radius of curvature equal to twice the focal length?

  回答

  (C)

  converging mirror
• 30

  When an object is placed at the centre of curvature of a concave mirror, its image is formed at

  回答

  (C)

  the centre of curvature
• 31

  A rectangular glass prism of thickness d and absolute refractive index n is placed on a point object which is viewed vertically downward from above the prism. Which of the following expressions correctly defines the apparent upward displacement of the object?

  回答

  (A)

  \(\frac{d}{n}\)
• 32

  Which of the following factors can affect the speed of sound in air? i. The temperature of the surrounding ii. The direction of the wind iii. The pitch of the sound.

  回答

  (A)

  i and ii only
• 33

  A sounding tuning fork is brought near the open end of a pipe containing air and the loudness of the sound is observed to increase. This observation is due to

  回答

  (B)

  resonance
• 34

  Which of the following statements about sound wave is not correct? Sound waves can be

  回答

  (D)

  polarized
• 35

  A dry plastic comb used in combing hair was found to attract pieces of paper and dust. The most probable explanation for this phenomenon is that the comb has been given

  回答

  (D)

  electric charges by friction
• 36

  Which of the following statements is correct about resonance? Resonance occurs when a body

  回答

  (B)

  is forced to vibrate on its own natural frequency by another body at the same vibration
• 37

  Which of the following components is used for storing electric charges?

  回答

  (C)

  capacitor
• 38

  Which of the following operations does not represent an action of a force field?

  回答

  (D)

  pushing of a wheel-barrow on a level gound
• 39

  A bulb marked 240V, 40W is used for 30 minutes. Calculate the heat generated

  回答

  (D)

  72000J
• 40

  Five 80-W and three 100W are run for 8 hours. If the cost of energy is N5.00 per unit, calculate the cost of running the lamp. [1 unit = 1 kWh]

  回答

  (B)

  N28.00
• 41

  Which of the following electromagnetic wave can be detected by its heating effect?

  回答

  (D)

  infrared radiation
• 42

  If a gas is excited by high voltage to produce a discharge and the light is examined in a spectrometer

  回答

  (C)

  an emission spectrum is observed
• 43

  The number of protons in an element increased by one after a radioactive decay. The element must have decay by emitting

  回答

  (A)

  a beta particle
• 44

  In a nuclear reactor, chain reactions result from the release of

  回答

  (C)

  neutrons
• 45

  The correct sequence of energy transformation in the operation of an x-ray tube is i. X-rays ii. Kinetic energy of thermo electrons iii. Potential energy of the target atoms iv. Heat energy of the emitted electrons

  回答

  (C)

  iv, ii, iii, i