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JAMB - Physics (2003)

  • 1
    On top of a spiral spring of the force constant 500Nm-1 is placed a mass of 5 x 10-3 kg. If the spring is compressed downwards by a length of 0.02m and then released, calculate the height to which the mass is projected
    отговор
    (C)
    2 m
  • 2
    A test tube of radius 1.0cm is loaded to 8.8g. If is placed upright in water, find the depth to which it would sink
    отговор
    (A)
    2.8cm
  • 3

    The length of piece of glass block was measured by means of a vernier calliper as shown above. The length of the glass block is

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    (B)
    1.64 cm
  • 4
    A hose of cross-sectional area 0.5m2 is used to discharge water from a water tanker at a velocity of 60ms-1 in 20s into a container. If the container is filled completely, the volume of the container is
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    (B)
    600m 3
  • 5
    If an object just begins to slide on a surface inclined at 30o to the horizontal,the coefficient of friction is
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    (D)
    1/√3
  • 6
    Water does not drop through an open umbrella of silk materials unless the inside of the umbrella is touched. This is due to
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    (D)
    surface tension
  • 7
    The stylus of a phonograph record exerts a force of 7.7 x 10-2N on a groove of radius 10-5m. Compute the pressure exerted by the stylus on the groove
    отговор
    (A)
    2.45 x 108 Nm-2
  • 8
    A piece of stone attached to one end of a string is whirled round in a horizontal circle and the string suddenly cuts. The stone will fly off in a direction
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    (C)
    tangential to the circular path
  • 9
    A 90cm uniform lever has a load of 30N suspended at 15cm from one of its ends. If the fulcrum is at the center of gravity, the force that must be applied at its other end to keep it in horizontal equilibrium is
    отговор
    (B)
    20N
  • 10
    A satellite is in a parking orbit if its period is
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    (C)
    equal to the period of the earth
  • 11
    TºC 0 5 10 15 20 40 60
    S.V.P(mmHg) 4.58 6.51 8.94 12.67 17.50 55.10 149.00


    The table above shows the saturation vapour pressure against temperature in a certain town. If the vapour pressure in this town at 20oC is 10mmHg, what is the relative humidity?

    отговор
    (B)
    57.0%
  • 12
    A turning fork of frequency 340Hz is vibrated just above a cylindrical tube of height 1.2m. If water is slowly poured into the tube, at what maximum height will resonance occur.
    [speed of sound in air = 340ms-1]
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    (A)
    0.95m
  • 13
    By what factor will the size of an object placed 10cm from a convex lens be increased if the image is seen on a screen placed 25cm from the lens?
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    (B)
    2.5
  • 14
    Thermal equilibrium between two object exist when
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    (A)
    the temperature of both objects are equal
  • 15
    An open pipe closed at one end produces its first fundamental note. If the velocity of sound in air is P and t the length of the pipe, the frequency of the note is
    отговор
    (C)
    v/4t
  • 16
    On a fairly cool rainy day when the temperature is 20oC, the length of a steel railroad track is 20m. What will be its length on a hot a dry day when the temperature is 40oC?
    [coefficient of linear expansion of steel = 11 x 10-6K-1]
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    (C)
    20.004m
  • 17
    If an object is placed between two parallel plane mirrors with their reflecting surfaces facing each other, how many images of the object will be formed?
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    (A)
    Infinite
  • 18
    The phenomenon where by the water droplets in the atmosphere combines with dust particles in the air to reduce visibility is
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    (D)
    fog
  • 19
    At what position will an object be placed in front of a concave mirror in order to obtain an image at infinity?
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    (B)
    At the principal focus
  • 20
    If the distance from a point source of sound is doubled, by what factor does the intensity decrease?
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    (A)
    4.00
  • 21
    A 2000W electric heater is used to heat a metal object of mass 5kg initially at 10oC. If a temperature rise of 30oC is obtained after 10min, the heat capacity of the material is
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    (B)
    4.0 x 104JoC-1
  • 22

    If 1.2 x 10^6J of heat energy is given off in 1 sec from a vessel maintained at a temperature gradient of 30Km-1, the surface area of the vessel is

    [ thermal conductivity of the vessel = 400Wm-1K-1]

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    (A)
    1.0 x 102m2
  • 23
    A positive charged rod X is brought near as uncharged metal sphere Y and is then touched by a finger with X still in place. When the finger is removed, the result is that y has
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    (D)
    a negative charge and a negative potential
  • 24
    In the diagram above, if each of the resistors can dissipate a maximum of 18W without becoming excessively heated, what is the maximum power the circuit can dissipate?
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    (A)
    27W
  • 25
    The operation of an optical fibre is based on the principal of
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    (C)
    refraction of light
  • 26
    I the diagram above, what would happen to the current I, if another resistor, R2, is connected in parallel to R1?
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    (C)
    It will increase because the effective resistance will decrease
  • 27
    A wire of 5Ω resistance is drawn out so that its new length is two times the original length. If the resistivity of the wire remains the same and the cross-sectional area is halved, the new resistance is
    отговор
    (B)
    20Ω
  • 28
    An electron of charge 1.6 x 10-19C is accelerated between two metal plates. If the kinetics energy of the electron is 4.8 x 10-17J, the potential difference between the plate is
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    (C)
    300V
  • 29
    A magnetic field is said to exist at a point if a force is
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    (B)
    exerted on a moving charge at the point
  • 30
    I It retains its magnetic much longer than steel.
    II It is more easily magnetized than steel
    III It is more easily demagnetized than steel
    IV It produces a stronger magnet than steel
    Which combination of the above makes iron preferable to steel in the making of electromagnets?
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    (D)
    II, III and IV only
  • 31
    Which of the following pairs of light rays show the widest separation in the spectrum of white light
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    (A)
    Blue and red
  • 32
    The most suitable cell used for short interval switches in electric bells is a
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    (C)
    Leclanche cell
  • 33
    A ray incident on a glass prism undergoes minimum deviation when the
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    (D)
    incident angle is equal to the angle of emergence
  • 34
    The count rate of a radioactive material is 800 count/min. If the half-life of the material is 4 days, what would the count rate be in 16 days later
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    (C)
    50 count / min
  • 35
    A circuit has an area of 0.4m2 and consists of 50 loops of wire. If the loops are twisted and allowed to rotate at a constant angular velocity of 10 rad s-1 in a uniform magnetic field of 0.4T, the amplitude of the induced voltage is
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    (D)
    80V
  • 36
    The force on a charge moving with velocity v in a magnetic field B is half of the maximum force when the angle between v and B is
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    (C)
    30o
  • 37
    The maximum kinetic energy of the photoelectron emitted from a metal surface is 0.34eV. If the work function of the metal surface is 1.83eV,find the stopping potential.
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    (D)
    0.34V
  • 38
    When an alternating current given by I = 10sin (120π)t passes through a 12Ω resistor, the power dissipated in the resistor is
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    (A)
    1200W
  • 39
    In a semi conductor junction diode, as the depletion or barrier layer is forward-biased, the layer
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    (B)
    narrows
  • 40
    The major difference between a pure semiconductor and a pure metal is that
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    (C)
    the resistance of metals increases with temperature, while for semiconductors, it is the reverse
  • 41
    When a nucleus is formed by bringing protons and neutrons together, the actual mass of the formed nucleus is less than the sum of the masses of the energy equivalent of this mass difference is the
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    (C)
    binding energy
  • 42
    A bead traveling on a straight wire is brought to rest at 0.2m by friction. If the mass of the bead is 0.01kg and the coefficient of friction between the bead and the wire is 0.1 determine the work done by the friction
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    (B)
    \( 2 \times 10^{-3}J \)
  • 43
    A ray of light is incident on an equilateral triangular glass prism of refractive index 3/2, Calculate the angle through which the ray is minimally deviated in the prism
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    (B)
    37.2\(^{\circ} \)
  • 44
    In the calibration of an ammeter using faraday's laws of electrolysis, the ammeter reading is kept constant at 1.2A. If 0.990g of copper is deposited in 40 minutes , the correction to be applied to the ammeter is
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    (C)
    0.05A
  • 45
    An electron makes a transition from a certain energy level Ek to the ground state E0. If the frequency of emission is 8.0 x 1014Hz The energy emitted is
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    (B)
    5.28 x 10-19J