JAMB - Physics (2011)

  • 1
    A man standing on a lift that is descending does not feel any weight because
    Răspuns
    (C)
    the lift's acceleration is same as acceleration due to gravity
  • 2
    Two balls X and Y weighing 5 g and 50 kg respectively were thrown up vertically at the same time with a velocity of 100 ms1 .How will their positions be one second later?
    Răspuns
    (D)
    X and Y both be 500 m from the point of throw
  • 3
    If it takes an object 3s to fall freely to the ground from a certain height, what is the distance covered by the object?
    Răspuns
    (C)
    45 m
  • 4
    An object of mass 2 kg moves with a velocity of 10 ms1 round at circle of radius 4 m. Calculate the centripetal force on the object
    Răspuns
    (C)
    50 N
  • 5
    A carpenter on top of a roof of 20.0m high dropped a hammer of mass 1.5 kg and it fell directly to the ground. the kinetic energy of the hammer just before hitting the ground is?

    [g = 10 ms-2]
    Răspuns
    (C)
    300 J
  • 6
    If a tube of small radius opened at both ends is placed in a liquid, the liquid will
    Răspuns
    (C)
    falls below the liquid level if the liquid does not wet the glass
  • 7
    An object weighs 22 kg in water and 30kg in air. what is the upthrust exerted by the liquid on the object.


    [g = 10 ms2]
    Răspuns
    (D)
    80 N
  • 8
    A metal of volume 40 cm3 is heated from 30 °c to 90 °c, the increase in volume is
    Răspuns
    (E)
    no correct option
  • 9
    A copper wire was subjected to a tensile stress of 7.7 x 10\(^7\). Calculate the strain of the wire.
    [Young modules = 1.1 x 10\(^11\) Nm\(^{-2}\)]
    Răspuns
    (C)
    7.0 x 10-4
  • 10
    I. High thermal capacity.
    II. High sensitivity.
    III.Easy readability.
    IV. Accuracy over a wide range of temperature
    From the statement above, the qualities of a good thermometer are
    Răspuns
    (D)
    II, III and IV
  • 11
    A machine is used to lift a load of 20 N through a height of 10 m. if the efficiency of the machine is 40%, how much work is done?
    Răspuns
    (B)
    500 J
  • 12
    I. Density of the liquid.
    II. Depth below the surface of the liquid.
    III. Surface area of the liquid.
    In which of the statement above will pressure be dependent?
    Răspuns
    (A)
    I and II only.
  • 13
    Which of the following could be effectively used to reduce friction?
    Răspuns
    (B)
    grease
  • 14
    Which of the following types of waves needs a medium for propagation?
    Răspuns
    (A)
    sound waves
  • 15
    Which of the following electromagnetic waves has the highest frequency?
    Răspuns
    (C)
    x - rays
  • 16
    A perfect emitter or absorber of radiant energy is a
    Răspuns
    (B)
    black body
  • 17
    The ground is always cold at night because the
    Răspuns
    (B)
    earth radiates heat to the atmosphere at night
  • 18
    A cannon is fired from town X,after how long is the sound heard at a town Y 4.95 km away?



    [velocity of sound in the air = 330 ms-1]
    Răspuns
    (D)
    15 s
  • 19
    The phenomenon that shows that increase in pressure lowers the melting point can be observed in
    Răspuns
    (D)
    regelation
  • 20
    A block of aluminum is heated electrically by a 30 w heater if the temperature rises by 10°c in 5 minutes, the heat capacity of the aluminum is
    Răspuns
    (A)
    900 JK-1
  • 21
    Steam burn is more severe than that of boiling water because
    Răspuns
    (B)
    steam possesses greater heat energy per unit mass
  • 22
    I. change of state
    II. Diffusion
    III. Radiation
    IV. Osmosis
    which of the processes above can be explained using the kinetic theory?
    Răspuns
    (D)
    I, II and IV
  • 23
    Three similar cells each of e.m.f 2 v and internal resistance 2Ω are connected in parallel, the total e.m.f and total internal resistance are respectively
    Răspuns
    (B)
    2 v, 0.7Ω
  • 24
    When the human eye loses its power of accomodation, the defect is known as
    Răspuns
    (B)
    presbyopia
  • 25
    When a red rose flower is observed in blue light, what colour does the observer see?
    Răspuns
    (E)
    No correct option
  • 26
    The capacitance of a parallel plate capacitor is 20 μf in air and 60 μf in the presence of a dielectric. What is the dielectric constant?
    Răspuns
    (C)
    3.0
  • 27
    A certain far - sighted person cannot see object that are closer to the eye than 50 cm clearly. Determine the power of the converging lens which will enable him to see at 25 cm
    Răspuns
    (B)
    0.02 D
  • 28
    The eclipse of the sun occurs when the
    Răspuns
    (A)
    moon is between the sun and the earth
  • 29
    Which of the following is a property of steel?
    Răspuns
    (C)
    it can be used for making permanent magnets
  • 30
    In measuring high frequency a.c, the instrument used is the
    Răspuns
    (D)
    hot wire ammeter
  • 31
    If the charge of electricity is K wh is N4, what is the cost of operating an electrical appliance rated 250 v,2 A for six hours?
    Răspuns
    (B)
    N12
  • 32
    Under which of the following conditions do gases conduct electricity?
    Răspuns
    (B)
    low pressure and high p.d
  • 33
    Two inductors of inductance 4 II and 8 II are arrange in series and a current of 10 A is passed through them. What is the energy stored in them?
    Răspuns
    (A)
    600 J
  • 34
    Which of the following materials has an increase in resistance with temperature?
    Răspuns
    (B)
    metals
  • 35
    The bond between silicon and germanium is
    Răspuns
    (A)
    covalent
  • 36
    A radioactive isotope has a decay constant of 10-5s4. Calculate half life
    Răspuns
    (C)
    6.93 x104s
  • 37
    The electrical properties of germanium can be altered drastically by the addition of impurity. This process is referred to as
    Răspuns
    (D)
    dopping
  • 38
    If the threshold frequency for tungsten is 1.3 x 1015Hz, what is its work function?


    [H = 6.6 x 10-34 Js]
    Răspuns
    (A)
    8.58 x 10-19 J
  • 39
    Which of the following will be applied when a metal Y is used to electroplate another metal X in electrolysis?
    Răspuns
    (D)
    Y is the anode and very high current is used
  • 40
    The diagram above shows two vectors at right angles to each other. The value of the resultant vector is
    Răspuns
    (B)
    10.0 N
  • 41
    The diagram above show the positions of a cone. The position which can be described as neutral equilibrium is represented as
    Răspuns
    (A)
    Z only
  • 42
    The correct expression for the potential at a point distance r from a charge q in an electric field is?
    Răspuns
    (D)
    \(\frac{q}{4πε_or}\)
  • 43
    An image in a convex lens is upright and magnified 3 times. If the focal length of the lens is 15 cm, what is the object distance?
    Răspuns
    (A)
    10 cm
  • 44
    A length of wire has a frequency of 225Hz when stretched by a force of 225N. If the force increased to 324N, what is the new frequency of vibration?
    Răspuns
    (A)
    270 Hz
  • 45

    In the circuit above, three resistors, 2Ω, 4Ω and 12Ω are connected in parallel and a 12V battery is connected across the combination. The current flowing through the 12Ω resistors is

    Răspuns
    (B)
    1.0 A