WAEC - Physics (2022)

• 1

  The area under a force-time graph represents--------

  回答

  (B)

  change in momentum
• 2

  From the principle of flotation, a body sinks in a fluid until it displace a quantity equal to its own?

  回答

  (C)

  weight
• 3

  The length of a simple pendulum is increased by a factor of four. By what factor is its period increase?

  回答

  (B)

  2
• 4

  The linear expansivity, \(\alpha\), and cubic expansivity, \(\gamma\), of a material are related by the equation?

  回答

  (B)

  \(\gamma\)=3\(\alpha\)
• 5

  

  Suppose three identical steel balls Q, R, and S, are placed on an undulating ground as illustrated in the diagram above. Which of the balls is/are in neutral equilibrium?

   

  回答

  (C)

  R only
• 6

  

  Which of the illustrated graphs above represents a body moving with uniform retardation?

  回答

  (D)

  D
• 7

  The correct relationship between the displacement, s, of a particle initially at rest in a linear motion and the time, t, is?

  回答

  (D)

  s \(\alpha\) t\(^{2}\)
• 8

  The joule is equivalent to?

  回答

  (C)

  Kg m\(^{2}\) s\(^{-2}\)
• 9

  Which of the following statement(s) is/are correct about a fixed mass of gas compressed in an inexpansible container;

  I. The average speed of the molecules increases

  II. The temperature of the gas increases

  III. The molecules hit the walls of the container more often than before the compression 

  回答

  (C)

  I, II, and III only
• 10

  An example of a mechanical wave is---------

  回答

  (A)

  water waves
• 11

  Which of the following descriptions of the image formed by a plane mirror is not correct. the image is----

  回答

  (C)

  erect and bigger than the object
• 12

  The efficiency of a wheel and axle is 100% and the ratio of their radii is 5:1. calculate the effort required to lift a load of mass 20kg using this machine, [g = 10 m s\(^{-2}\)]

  回答

  (C)

  40N
• 13

  A freely suspended compass needle on the earth's surface settles in a plane called----------

  回答

  (B)

  magnetic meridian
• 14

  An object is placed at different distances, u, from a converging lens of focal length, 15.0cm. For what value of u does the lens act as a microscope?

  回答

  (C)

  M < 15cm only
• 15

  The periodic rise and fall in the intensity of sound produced whn two notes of nearly equal frequencies are sounded together is called?

  回答

  (B)

  beat
• 16

  The power of the lens is +2.5D. What is the radius of the curvature?

  回答

  (D)

  80.0 cm
• 17

  The reason for having a large number of turns in the coil of a moving coil galvanometer is to--------

  回答

  (B)

  increase the sensitivity of the galvanometer
• 18

   Current is passed through two parallel conductors in the same direction. If the conductors are placed near each other, they will------------------

  回答

  (D)

  attract each other
• 19

  The period of a 10 kHz radio wave traveling at 10\(^{8}\) ms\(^{-1}\) is--

  回答

  (B)

  1.0 x 10\(^{-4}\) s
• 20

  The magnetic material produced from the chemical combination of metal oxides and has a very high resistance to electric current is called 

  回答

  (A)

  ferrite substance
• 21

  A body of mass, M, moving with velocity, V, has a wavelength, X, associated with it. This phenomenon is called----------

  回答

  (D)

  wave-particles paradox
• 22

  Which of the following statements about a straight current-carrying wire placed in a uniform magnetic field is correct? The wire experiences ---------------

  回答

  (B)

  no motor force of it is parallel to the field
• 23

  Three cells each of emf, 1.0 V, and internal resistance, 2 \(\Omega\), are connected in parallel across a 3\(\Omega\)  resistor. Determine the current in the resistor.

  回答

  (C)

  0.30A
• 24

  Which of the following statements about electric potential energy is not correct?

  回答

  (C)

  The electric potential energy of a positively charged particle decreases when it moves to a point of higher potential
• 25

  A galvanometer with a full-scale deflection of 20 mA is Converted to read 8 K by connecting a 395 \(\Omega\) resistor in series with it. Determine the internal resistance of the galvanometer

  回答

  (B)

  5.0\(\Omega\)
• 26

  .An inductor of inductance 10 H is connected across an a.c circuit source of 50 V, 100 Hz. What is the current in the circuit? [\(\pi\) = 3.14]

  回答

  (D)

  0.008A
• 27

  The speed of fast-moving neutrons in a nuclear reactor can be reduced by using?

  回答

  (A)

  graphite rods
• 28

  In a series R-L-C circuit at resonance, impedance is----

  回答

  (B)

  minimum
• 29

  A lamp is rated 240 V, 60 W. Determine the resistance of the lamp when lit?

  回答

  (D)

  960\(\Omega\)
• 30

  One major reason why electrical appliances in homes are normally earthed is that the-----------

  回答

  (A)

  person touching the appliance is safe from electric shock
• 31

  In doping an intrinsic semiconductor to produce a p-type semiconductor,

  回答

  (C)

  an acceptor element is added
• 32

  Arrange the following radiations in order of increasing ionization of air.

  I. Alpha

  Il. Gamma

  IIl. Beta

  回答

  (C)

  II < III < I
• 33

  If the kinetic energy of an electron is 100 eV, what is the wavelength of the de-Broglie wave associated with it? [h = 6.6 x 10\(^{-34}\) J s, e = 1.6 x 10\(^{-19}\)C, m\(_{e}\), = 9.1 x 10\(^{-31}\) kg]

  回答

  (A)

  1.22 x 10\(^{-10}\)m
• 34

  Gamma rays are produced when?

  回答

  (B)

  energy changes occur within the nuclei of atoms
• 35

  The half-life of a radioactive substance is 15 hours. If at some instance, the sample has a mass of 512 g, calculate the time it will take \(\frac{7}{8}\) of the sample to decay

  回答

  (C)

  45 hours
• 36

  When the direction of vibration of the particles of a medium is perpendicular to the direction of propagation of a wave, the wave is said to be--------

  回答

  (B)

  transverse
• 37

  A hunter fires a gun at a point 408 m away from a cliff. If he hears an echo 2.4 s later, determine the speed of the sound wave

  回答

  (A)

  340 ms\(^{-1}\)
• 38

  The distance between the fixed points of a mercury-in-glass thermometer is 30 cm. Determine the temperature when the mercury level is 10.5 cm above the lower fixed point

  回答

  (C)

  35.0 ºC
• 39

  Which of the following statements-about electromagnetic waves is not correct?

  回答

  (C)

  They are longitudinal
• 40

  The diameter of a brass ring at 30 °C is 50.0 cm. To what temperature must this ring be heated to increase its diameter to 50.29 cm? [ linear expansivity of brass = 1.9 x 10\(^{-5}\) K\(^{-1}\)]

  回答

  (D)

  335.3 °C
• 41

  Which of the following concepts is a method of heat transfer that does not require a material medium?

  回答

  (D)

  Radiation
• 42

  Which of the folowing statements about light travelling from one material medium to another is not correct?

  回答

  (D)

  Its frequency changes.
• 43

  The engine of a car provides a forward force of 1240 N and the total resistive force on the car is 800N. If the mass of the car is 1220 kg, determine the distance the car has to travel from the rest before acquiring a speed of 4 m s\(^{-1}\).

  回答

  (B)

  22.2 m
• 44

  A quantity of water at 0 °C is heated to 30 °C. For each degree rise in temperature, its density will---------

  回答

  (D)

  rise and then falls
• 45

  A small object of mass 50 g is released from a point A. Determine the velocity of the object when it reaches a point B, a vertical distance of 30m below A. [g = 10 ms\(^{-2}\)

  回答

  (D)

  24.5 m s\(^{-1}\)