JAMB - Physics (1992)

  • 1
    What is the least possible error in using a rule graduated in centimeters?
    Responder
    (A)
    0.1cm
  • 2
    Which of the following affects the period of a simple pendulum? i. mass of the pendulum bob. ii. length of the pendulum. iii. acceleration due to gravity.
    Responder
    (B)
    ii and iii only
  • 3
    A boy sits in a train moving with uniform speed on a straight track. If from his outstretched palm he gently tosses his coin upwards, the coin will fall
    Responder
    (D)
    into his palm
  • 4
    A body starts from rest and moves with a uniform acceleration of 6 ms \(^{-2}\). What distance does it cover in the third seconds
    Responder
    (A)
    15m
  • 5
    A stone, Q is thrown with velocity U at an angle of 75o to the horizontal. Another stone R is thrown with the same velocity U but with an angle of 15o to the horizontal. The ranges covered by the stones will be
    Responder
    (C)
    the same for Q and R
  • 6
    A man weight 800N climbs up a stairs to height of 15m in 12.5s. What is the man''s average power output?
    Responder
    (C)
    960W
  • 7
    A machine requires 1000J of work to raise a load of 500N through a vertical distance of 1.5m. Calculate the efficiency of the
    Responder
    (B)
    75%
  • 8
    In an experiment to determine Young's Modulus for a wire, several loads are attached to the wire and the corresponding extension measured. The tensile stress in each case depends on the
    Responder
    (B)
    load and the radius of the wire
  • 9
    If a plastic sphere floats in water (density = 1000kgm3) with 0.5 of its volume submerged, and floats in oil with 0.4 of its volume submerged the density of the oil is
    Responder
    (C)
    1250kgm3
  • 10
    A platinum resistance thermometer wire has a resistance of 5 ohms at 0oC and 5.5 ohms at 100oC. Calculate the temperature of the wire when the resistance is 5.2 ohms
    Responder
    (C)
    40oC
  • 11
    A bridge made of steel is 600m long. What is the daily variation in its length if the night-time and daytime temperatures are 10°C and 35°C respectively. The linear expansivity of steel is 0.000012C\(^{-1}\).
    Responder
    (C)
    18.00cm
  • 12
    One of the most important applications of bi-metallic strip is found in the construction of
    Responder
    (A)
    a thermostat
  • 13
    At constant pressure, the density of a fixed mass of gas is
    Responder
    (C)
    inversely proportional to its temperature
  • 14
    How much heat is absorbed when a block of copper of mass 0.05kg and specific heat capacity 390Jkg-1K-1 is heated from 20oC to 70oC?
    Responder
    (B)
    9.75 x 102J
  • 15
    A block of ice floats on water inside a container. If the block of ice gets completely melted, the level of water in the container will
    Responder
    (B)
    remain the same
  • 16
    The space between the double glass walls of a thermos flask is evacuated space are silvered. The residual source of heat loss takes place by
    Responder
    (C)
    conduction through the stopper and the glass
  • 17
    The equation of a wave is y = 0.005 sin[x(0.5X - 200t)] where x and y are in meters and t is in seconds. What is the velocity of the wave?
    Responder
    (B)
    400ms-1
  • 18
    Which of the following characteristics of a wave is used in the measurement of the depth of the sea?
    Responder
    (D)
    reflection
  • 19
    A note is the octave of another note if it has
    Responder
    (A)
    a frequency twice that of the first note
  • 20
    What is the frequency of the sound made by a siren having a disc with 32 holes and making 25 revolution per seconds?
    Responder
    (C)
    800Hz
  • 21
    Which of the following properties make the convex mirror useful as a driving mirror? i. the image is real. ii. the image is erect. iii. it has a wide field of view. iv. the image is magnified.
    Responder
    (C)
    ii and iii
  • 22
    When an object is placed very close to the pole of a concave mirror, the virtual image obtained is
    Responder
    (D)
    enlarged and upright
  • 23
    A concave mirror has a radius of curvature of 36cm. At what distance from the mirror should an object be placed to give a real image three times the size of the object?
    Responder
    (B)
    24cm
  • 24
    Which of the following statements is CORRECT about a long-sighted boy who does not put on glasses?
    Responder
    (D)
    Parallel rays of light are focused behind his retina
  • 25
    The speed of light in air is 3 x 10\(^8\)ms\(^{-1}\). What is the speed in glass with a refractive index of 1.50?
    Responder
    (C)
    2.0 x 108ms-1
  • 26
    If the refractive index of a medium in air is 2.0, what is the critical angle for this medium?
    Responder
    (A)
    30o
  • 27
    Which of the following arrangements of the components of electromagnetic spectrum is in ascending order of wavelengths?
    Responder
    (B)
    Gamma rays, X-rays, ultraviolet rays, infra-red rays
  • 28
    The angle between the direction of the earth's magnetic field and the horizontal is called the
    Responder
    (D)
    angle of dip
  • 29
    Calculate the force acting on an electron of charge 1.6 x 10-19C placed in an electric field of intensity 108Vm-1
    Responder
    (A)
    1.6 x 10-11N
  • 30
    When an ebolite rod is rubbed with fur, it has
    Responder
    (B)
    a negative charge
  • 31
    Which of the following factors has no effect on the e.m.f. of a primary cell?
    Responder
    (B)
    size of the cell
  • 32
    A wire of length 15m made of a material of resistivity 1.8 x 10-6\(\Omega\)m has a resistance of 0.27\(\Omega\). Determine the area of the wire
    Responder
    (B)
    1.0 x 10-4m2
  • 33
    A 5-v battery is connected across the plates of a 2.0\(\mu\)F uncharged parallel plate capacitor. The charge on the capacitor after a long time is
    Responder
    (B)
    10.0\(\mu\)C
  • 34
    Which of the following apparatus will require the smallest fuse rating for its protection?
    Responder
    (A)
    60W, 240V
  • 35
    The heat produced in a conductor carrying an electric current is
    Responder
    (D)
    directly proportional to the square of the current, the resistance and the time
  • 36
    The maximum permissible current through a galvanometer G of internal resistance 10\(\Omega\) is 0.05A. A resistance R is used to convert G into a voltmeter with a maximum reading of 100V. Find the value of R and how it is connected to G
    Responder
    (C)
    1990 ohms in series
  • 37
    In alternating current theory, the units of impedance, r.m.s. voltage and resonance frequency are respectively equal to
    Responder
    (B)
    ohms, volt and hertz
  • 38
    In A.C circuit theory, the root means square (r.m.s) current, Irms and the peak (maximum)current Io are related by
    Responder
    (B)
    Irms = \(\frac{I_o}{\sqrt{2}}\)
  • 39
    The threshold of frequency for photoelectric effect depends on the
    Responder
    (C)
    material of the photocathode
  • 40
    After three half lifes, the fraction of a radioactive material that has decayed is
    Responder
    (D)
    \(\frac{7}{8}\)
  • 41
    \(^{27}_{13}Al\) + \(^{1}_{0}n\) \(\Rightarrow\) \(^{24}_{11}Na\) + X
    Responder
    (D)
    an alpha particle
  • 42
    A uniform light rod is kept in horizontal equilibrium under the influence of fore forces as shown above, which of the following equations correctly represents the condition of equilibrium for the rod
    Responder
    (D)
    F1a + F2b - F3c - F4d = 0
  • 43

    In the diagram above, the hanging mass \(m_2\) is adjusted until \(m_1\) is on the verge of sliding. The coefficient of static friction between the mass \(m_1\) and the table is

    Responder
    (C)
    m2/m1
  • 44

    The fig above shows the heights of two liquids X and Y when some air is sucked out of the apparatus through the pump P. The diameter of the table in X is twice That of the Tube In Y. What is the relative density of the liquid X with respect to liquid Y

    Responder
    (C)
    3
  • 45
    The diagram above represents the field pattern obtained by bringing the poles of two magnets together.The poles must be
    Responder
    (A)
    S-S poles