WAEC - Physics (2018)

• 1

  The S.I unit for sound energy is

  תְשׁוּבָה

  (D)

  J
• 2

  The general definition of elastic modulus is

  תְשׁוּבָה

  (A)

  \(\frac{stress}{strain}\)
• 3

  

  The diagram above illustrates a simple barometer. Which distance measures the atmospheric pressure?

  תְשׁוּבָה

  (B)

  QR
• 4

  The property of a body to remain at rest or to continue in uniform motion in a straight line is called

  תְשׁוּבָה

  (B)

  Inertia
• 5

  During a training session, two footballers pass a ball repeatedly between each other. The 'to and fro' motion of the ball is not simple harmonic because the

  I. Acceleration of the ball is not directed towards a fixed point

  II. Restoring force is not directed towards the centre

  III. Acceleration of the ball is not directly proportional to the displacement from a fixed point

  Which of the statements above are correct?

  תְשׁוּבָה

  (A)

  I and III only
• 6

  A dam is able to hold a large quantity of water because its wall is

  תְשׁוּבָה

  (C)

  thickest at the bottom
• 7

  A body of mass m moving around a circle of radius r with a uniform speed v experiences a centripetal force F. The work done by the centripetal force on it is

  תְשׁוּבָה

  (B)

  zero
• 8

  

  A block is acted upon by TWO horizontal forces as illustrated in the diagram above. The block accelerates at 1.5\(ms^{-2}\). Calculate the mass of the block.

  תְשׁוּבָה

  (A)

  6kg
• 9

  Which of the following quantities are dimensionally independent?

  I. Dielectric constant   II. Momentum   III. Efficiency   IV. Refractive index

  תְשׁוּבָה

  (D)

  I, III and IV
• 10

  A body is projected with an initial velocity u at angle \(\theta\) to the horizontal. If \(R_{max}\) is the maximum range of the projectile, what does the relation \(\frac{u^{2}}{R_{max}}\) represent?

  תְשׁוּבָה

  (B)

  Acceleration due to gravity
• 11

  An object at rest is said to possess 

  תְשׁוּבָה

  (A)

  potential energy
• 12

  According to Newton's law of cooling, the heat energy lost per unit area of a body depends on the

  I. Surface area

  II. Nature of the surface

  III. Temperature of the surface

  IV. Excess temperature over the surroundings

  תְשׁוּבָה

  (C)

  I,II and III
• 13

  

  The graph of density against temperature for water is correctly illustrated by

  תְשׁוּבָה

  (C)

  III
• 14

  A football is kicked at an angle of 45° to the horizontal over a defense line up with a velocity of 15\(ms^{-1}\). Calculate the magnitudeof horizontal velocity of the ball at its highest point  [Neglect friction, g = 10\(ms^{-2}\)].

  תְשׁוּבָה

  (C)

  10.6\(ms^{-1}\)
• 15

  The ice point on the absolute scale of temperature is

  תְשׁוּבָה

  (A)

  0K
• 16

  Which of the following factors does not increase the rate of evaporation of water in a lake?

  תְשׁוּבָה

  (A)

  Increase in the pressure of the atmosphere
• 17

  The bob of a simple pendulum takes 8.0s to complete 10 oscillations. Determine the frequency of oscillation of the bob.

  תְשׁוּבָה

  (B)

  1.25Hz
• 18

  

  The diagram above illustrates the mercury-in-glass thermometer used for determining the temperature of a room. Use the data on it to determine the room temperature. 

  תְשׁוּבָה

  (D)

  30.0°C
• 19

  Frequency is measured in

  תְשׁוּבָה

  (C)

  hertz
• 20

  Which of the following electromagnetic waves is most energetic? 

  תְשׁוּבָה

  (C)

  Gamma rays
• 21

  Rainbow formation is a natural phenomenon illustrating that white light

  תְשׁוּבָה

  (D)

  is dispersed into its constituent colours after rainfall
• 22

  

  The lens illustrated above can best be described as a

  תְשׁוּבָה

  (B)

  plano-convex
• 23

  Two plane mirrors are inclined to each other such that an object placed between them has 11 images. Determine the angle of inclination 

  תְשׁוּבָה

  (A)

  30°
• 24

  The pitch of a note is not affected by

  תְשׁוּבָה

  (D)

  amplitude of sound wave
• 25

  When two flat plate conductors are arranged in such a way that they possess equal and opposite charges seperated by a dielectric, they form a/an

  תְשׁוּבָה

  (C)

  capacitor
• 26

  

  Which electrical device is illustrated above?

  תְשׁוּבָה

  (C)

  d.c. generator
• 27

  A simple barometer is constructed using a liquid \(Q_{1}\) of density 16.2\(g/cm^{3}\). Calculate the least lenth of the tube to be used to measure pressure of 1.5atm.  [Density of mercury = 13.6\(g/cm^{3}\), 1atm = 76.0 cm of Mercury]

  תְשׁוּבָה

  (D)

  638mm
• 28

  

  A bar AB is balanced horizontally on two knife edges as illustrated as in the diagram above. Determine the weight of the bar.

  תְשׁוּבָה

  (C)

  40.0N
• 29

  To obtain a virtual, erect and magnified image from a thin converging lens, an object must be placed 

  תְשׁוּבָה

  (A)

  between the focus and the lens
• 30

  

  The diagram above represents a transverse travelling wave. Which two points are 180° out of phase?

  תְשׁוּבָה

  (D)

  D and H
• 31

  Two objects P and Q of masses 100kg and 20kg respectively are 1.2m apart on a horizontal surface. Calculate the net gravitational force acting on Q.   \([G= 6.67 \times 10^{-11} Nm^{2}kg^{-2}]\)

  תְשׁוּבָה

  (D)

  \(9.26\times 10^{-8} N\) towards Q
• 32

  The primary of a transformer has 100 turns and its secondary has 200 turns. If the voltage at the primary is 100V, determine the voltage at the secondary.

  תְשׁוּבָה

  (C)

  200V
• 33

  

  In the diagram illustrated a block of mass M is at rest on a plane inclined at an angle \(\theta\) to the horizontal. As \(\theta\) increases, the velocity ratio of the plane

  תְשׁוּבָה

  (B)

  decreases
• 34

  When the speed of a car is halved, its kinetic energy is

  תְשׁוּבָה

  (B)

  quartered
• 35

  A wire of length 400cm is stretched between two fixed points. When plucked, its fundamental frequency is 150Hz. Calculate the speed of the wave produced.

  תְשׁוּבָה

  (C)

  1200\(ms^{-1}\)
• 36

  

  The diagram above illustrates a waveform. Determine the number of wavelengths in it

  תְשׁוּבָה

  (C)

  2\(\frac{1}{2}\)
• 37

  A resistor with fixed resistance value is called a

  תְשׁוּבָה

  (B)

  standard resistor
• 38

  Which of the following statements is not an advantage of an alkaline accumulator?

  תְשׁוּבָה

  (A)

  The electrolyte does not need attention
• 39

  

  The diagram above illustrates the wire connections to a three-pin plug. The wires P, Q and R respectively are:

  תְשׁוּבָה

  (B)

  neutral, earth and live
• 40

  Which of the following statements about parallel plate capacitors is/are correct?

  I. Capacitance of the capacitor  is inversely proportional to the distance between the plates

  II. Capacitors can filter a.c signals from d.c 

  III. Capacitors can store charges

  תְשׁוּבָה

  (D)

  I, II and III
• 41

  

  The circuit contains three ammeters A1, A2 and A3 with readings of A2 and A3 shown as indicated in the diagram. Determine the reading of A1.

  תְשׁוּבָה

  (B)

  3A
• 42

  Which of the following statements about magnetic lines of force is not correct? They

  תְשׁוּבָה

  (D)

  intersect one another
• 43

  In which of the following activities is an induction coil not useful?

  תְשׁוּבָה

  (D)

  A.C. power transmission
• 44

  In a series R-L-C circuit, R = 10\(\Omega\), \(X_{c}\)= 4\(\Omega\) and \(X_{L}\) = 9\(\Omega\). The impedance of the circuit is

  תְשׁוּבָה

  (D)

  11.2\(\Omega\)
• 45

  

  A student uses two compass needles to investigate the magnetic field around a bar magnet. Which of the following diagrams show the correct directions of the needles?

  תְשׁוּבָה

  (B)

  B