WAEC - Physics (1988)

• 1

  Which of the units of the following physical quantities are derived? I. Area II. Thrust III. Pressure IV. Mass

  回答

  (B)

  I, II, III only
• 2

  The slope of a striaght line displacement time graph indicates the

  回答

  (B)

  Uniform velocity
• 3

  A man will exact the greatest pressure on a bench when he

  回答

  (E)

  stand on toes of one foot
• 4

  When three coplanar and non-parallel forces are in equilibrium,
  I. they can be represented in magnitude and direction by the three sides of a triangle taken in order.
  II. their lines of action meet at a point.
  III. the magnitude of anyone equals the magnitude of the resultant of the other two.
  IV. any one force is the equilibrant of the other two.
  
  Which of the following statements above are correct?

  回答

  (D)

  I, II, III & IV
• 5

  A ball of mass 0.5kg moving at 10ms^-1 collides with another ball of equal mass at rest. If the two balls move off together after the impact, calculate their common velocity.

  回答

  (C)

  5.0ms^-1
• 6

  A body is projected into space with an initial velocity V0 at an angle, θ to the horizontal. Which of the following statements is/are correct about its motion?
  I. The total time of flight is (V0 Cosθ)/g.
  II. The maximum height is (V0 Sin 2θ)/2g.
  III. The range is (V02 Cos2θ)/g.

  回答

  (D)

  II only
• 7

  A catapult is used to project a stone. Which of the following energy conversions takes place as the stone is released?

  回答

  (D)

  The elastic potential energy of the catapult is converted into gravitational potential energy of the stone
• 8

  A ball is thrown vertically upwards from the ground with an initial velocity of 50ms^-1. What is the total time spent by the ball in the air? (g = 10ms^-2)

  回答

  (C)

  10.0s
• 9

  Which of the following correctly gives the relationship between linear speed V and angular speed ω of a body moving uniformly in a circle of radius r?

  回答

  (A)

  V = ωr
• 10

  The motion of a body is simple harmonic if the

  回答

  (C)

  Acceleration is directed towards a fixed point and proportional to its distance from the point
• 11

  Which of the following statements about the gaseous state of matter is not correct? The molecules of a substance is in gaseous state

  回答

  (D)

  have no intermolecular attractive force
• 12

  Which of the following cannot be used to measure the temperature of a substance?

  回答

  (E)

  change in color with temperature
• 13

  The clinical thermometer is characterized by having a

  回答

  (D)

  constriction
• 14

  A given mass of gas has a pressure of 80Nm^-2 at a temperature of 47^oC. If the temperature is reduced to 27^oC with the volume remaining constant, the new pressure is

  回答

  (B)

  75.0 Nm^-2
• 15

  Which of the following is a reason why a concrete floor feels colder to the bare feet than a mat on the same floor during the rainy season?

  回答

  (D)

  Concrete floor is a better conductor of heat than the mat
• 16

  In which of the following is the expansion of solids a disadvantage?

  回答

  (E)

  the balance wheel of a watch
• 17

  Which of the following best explains a person suffers more severe burns when his skin is exposed to steam than when boiling water is poured onto his skin?

  回答

  (B)

  steam posses greater heat energy per unit-mass than boiling water
• 18

  Which of the following statements about radiant heat is/are not correct?
  I. radiant heat cannot travel through a vacuum
  II. rough surfaces emit radiant heat more than polished surfaces
  III. Dark surfaces absorb radiant heat more than bright surfaces

  回答

  (A)

  I only
• 19

  0.5kg of water at 10^oC is completely converted to ice by extracting 188000J of heat from it. If the specific heat capacity of water is 4200J kg^-1C^-1, calculate the specific latent heat of fusion of ice.

  回答

  (D)

  334.0 KJ kg^-1
• 20

  The temperature at which the water vapour present in the air is just sufficient to saturate it is called the

  回答

  (D)

  dew point
• 21

  Which of the following instrument may be used to measure the relative humidity?

  回答

  (E)

  Hygrometer
• 22

  Which of the following will affect the saturation vapour pressure of a liquid?

  回答

  (A)

  Temperature of the liquid
• 23

  Which of the following statements is/are not correct about image formed by a plane mirror?
  I. The magnification produced is 1
  II. The image distance is same as the object distance
  III. The image is real
  IV. The image is laterally inverted

  回答

  (C)

  III only
• 24

  A transparent rectangular block 5.0cm thick is placed on a black dot. The dot when viewed from above is seem 3.0cm from the top of the block calculate the refractive index of the material of the block.

  回答

  (D)

  5/3
• 25

  The velocities of light in air and glass are 3.0 x10\(^8\)ms\(^{-1}\) and 1.8 \(\times \)10\(^8\) ms\(^{-1}\) respectively. Calculate the sine of the angle of incidence that will produce an angle of refraction of 30° for a ray of light incident on glass.

  回答

  (C)

  0.8
• 26

  An object is placed 36cm from a converging lens of focal length 24cm.If a real image which is 4cm high is formed, Calculate the height of the object.

  回答

  (A)

  2.0cm
• 27

  The ability of the eye to focus objects at different distances is called

  回答

  (B)

  accommodation
• 28

  The change of the direction of a wave-front because of a change in the velocity of the wave in another medium is called?

  回答

  (A)

  refraction
• 29

  A source of sounds produces waves in air of wavelength1.65m. If the speed of sound in air is 330ms-1 the period of vibration in seconds is

  回答

  (E)

  0.005
• 30

  Which of the following statement s is/are not correct about a standing wave? I. It is formed by the superimposition of two progressive waves traveling in the same direction II. All points on the wave are vibrating with maximum displacement III. It is formed by the superimposition of two progressive waves of different amplitudes traveling in opposite directions

  回答

  (E)

  I,II and III
• 31

  A boy standing a distance from the foot of a tall cliff claps his hands and hears an echo 0.5s later. If the speed of sound is 340ms1, how far is he from the cliff?

  回答

  (C)

  85m
• 32

  A sounding tuning fork is brought near the end of a pipe containing an air column and the loudness of the sound increases. This effect is due to

  回答

  (C)

  resonance
• 33

  If the leaves a positively charged electroscope collapse completely as an object is brought near the cap of the electroscope, the objects possesses

  回答

  (E)

  an equal amount of negative charge
• 34

  A transformer with 5500 turns in its primary is used between a 240V a. c supply and a 120V kettle. Calculate the number of turns in the secondary

  回答

  (B)

  2750
• 35

  Local action is normally prevented from taking place in a simple electric cell by

  回答

  (C)

  amalgamating the surface of the zinc plate
• 36

  A cell can supply current of 0.8A and 0.4A through a 2Ω and a 3Ω resistors respectively. Calculate the internal resistance of the cell.

  回答

  (C)

  1.0Ω
• 37

  A battery of emf 24V and internal resistance 4Ω is connected to a resistor of 32Ω. What is the terminal p.d of the battery?

  回答

  (B)

  21.3V
• 38

  Two parallel conductors carry equal currents in the same direction. Which of the following statement is not a correct observation?

  回答

  (E)

  The two conductors will repel each other
• 39

  It takes 4 minutes to boil a quantity of water electrically. How long will it take to boil same quantity of water using the same heating coil but with the current doubled? (neglecting any external heat loss).

  回答

  (E)

  1 minute
• 40

  A lamp is marked 220V 60 W. Calculate the energy it would consume when connected to a 220V source for 1 hour.

  回答

  (A)

  216000J
• 41

  What is the effect of using split-rings in a simple d.c motor?

  回答

  (C)

  The current in the coil becomes alternating
• 42

  Which of the following statement is not correct about loaded spiral spring?

  回答

  (C)

  Up to the yield limit, extension is no longer proportional to the applied load.
• 43

  Calculate the resistivity of a wire of length 2m and cross-sectional area 0.004cm² if the resistance is 3.0 Ω.

  回答

  (B)

  0.006Ωcm
• 44

  Which of the following particles of ray has the highest penetrating power?

  回答

  (C)

  Gamma particles
• 45

  When sugar at the bottom of a glass of water gradually dissolves, the water level does not change applicably. Which of the following statements best describe this?

  回答

  (E)

  Water molecules are separated by large spaces between them
• 46

  Which of the following explains the concave meniscus of water in a glass tube?

  回答

  (A)

  The adhesion between water and glas is greater than the cohesion between water molecules
• 47

  The unit of inductance is the

  回答

  (B)

  henry
• 48

  Which of the following is/are not correct about isotopes of an element? The have

  回答

  (A)

  the same neutron number
• 49

  Which of the following is/are not affected by a magnetic field?
  I. Neutrons
  II. Cathode rays
  III. Alpha particles

  回答

  (A)

  I only
• 50

  An electron of charge 1.6 x 10¹⁹C is accelerated in vacuum from rest at zero volt towards a plate of 40KV. Calculate the kinetic energy of the electron.

  回答

  (D)

  6.4 x 10^-15 J