JAMB - Physics (1999)

  • 1
    The inner diameter of a test tube can be measured accurately using a?
    Відповідь
    (D)
    pair of vernier calipers
  • 2
    Two bodies have masses in the ratio 3:1. They experience forces which impart to them acceleration in the ratio 2:9 respectively. Find the ratio of forces the masses experienced.
    Відповідь
    (C)
    2 : 3
  • 3
    Particles of mass 10\(^{-2}\)kg is fixed to the tip of a fan blade which rotates with angular velocity of 100rad-1. If the radius of the blade is 0.2m, the centripetal force is
    Відповідь
    (B)
    20 N
  • 4
    A lead bullet of mass 0.05kg is fired with a velocity of 200ms\(^{-1}\) into a lead block of mass 0.95kg. Given that the lead block can move freely, the final kinetic energy after impact is
    Відповідь
    (A)
    50 J
  • 5
    A ball of mass 0.1kg is thrown vertically upwards with a speed of 10ms-1 from the top of a tower 10m high. Neglecting air resistance, its total energy just before hitting the ground is

    (take g = 10ms-2)
    Відповідь
    (C)
    15 J
  • 6
    A car of mass 800kg attains a speed of 25m/s in 20 secs. The power developed in the engine is
    Відповідь
    (A)
    1 . 25 x 104 W
  • 7
    When the brakes in a car are applied, the frictional force force on the tyres is
    Відповідь
    (D)
    is an advantage because it is in the opposite direction of the motion of the car
  • 8
    If the stress on a wire is 10\(^7\)Nm\(^{-2}\) and the wire is stretched from its original length of 10.00 cm to 10.05 cm. The Young's modulus of the wire is
    Відповідь
    (D)
    2 . 0 x 109 Nm-2
  • 9
    A solid weigh 10 .00 N in air, 6 N when fully immersed in water and 7 . 0 N when fully immersed in a liquid X. Calculate the relative density of the liquid, X.
    Відповідь
    (C)
    3/4
  • 10
    When temperature of a liquid increases, its surface tension
    Відповідь
    (A)
    Decreases
  • 11
    A gas at a volume of V0 in a container at pressure P0 is compressed to one-fifth of its volume. What will be its pressure if the magnitude of its original temperature T is constant?
    Відповідь
    (D)
    5P0
  • 12
    A piece of substance of specific head capacity 450JKg-1K-1 falls through a vertical distance of 20m from rest. Calculate the rise in temperature of the substance on hitting the ground when all its energies are converted into heat. [g = 10ms-2]
    Відповідь
    (B)
    4/9°C
  • 13
    I. A liquid boils when its saturated vapour pressure is equal to the external pressure
    II. Dissolved substances in pure water lead to increase in the boiling point.
    III. When the external pressure is increased, the boiling point increases.
    IV. Dissolved substances in pure water decrease the boiling point.

    Which combination of the above are peculiarities of the boiling point of a liquid?
    Відповідь
    (A)
    I, II and III
  • 14
    The temperature gradient across a copper rod of thickness 0.02m, maintained at two temperature junctions of 20°C and 80°C respectively is
    Відповідь
    (B)
    3.0 x 103Km-1
  • 15
    Calculate the mass of ice that would melt when 2kg of copper is quickly transferred from boiling water to a block of ice without heat loss.
    Specific heat capacity of copper = 400JKg-1K-1
    Latent heat of fusion of ice = 3.3 x 10\(^5\)JKg-1
    Відповідь
    (A)
    8/33kg
  • 16
    The equation of a wave traveling along the positive x-direction is given by;
    y = 0.25 x 10\(^{-3}\) sin (500t - 0.025x).
    Determine the angular frequency of the wave motion.
    Відповідь
    (C)
    5.00 x 102rad s-1
  • 17
    If a sound wave goes from a cold air region to a hot air region, its wavelength will
    Відповідь
    (A)
    increase
  • 18
    The lowest note emitted by a stretched string has a frequency of 40Hz. How many overtones are there between 40hz and 180Hz?
    Відповідь
    (B)
    3
  • 19
    A man stands 4m in front of a plane mirror. If the mirror is moved 1m towards the man, the distance between him and his new image is
    Відповідь
    (C)
    6m
  • 20
    The inside portion of part of a hollow metal sphere of diameter 20cm is polished. The portion will therefore form a
    Відповідь
    (C)
    convex mirror of focal length 5cm
  • 21
    The velocities of light in air and glass are 3.0 x 108ms-1 and 2.0 x 108ms-1 respectively. If the angle of refraction is 30°, the sine of the angle of incidence is
    Відповідь
    (D)
    0.75
  • 22
    An astronomical telescope is said to be in normal adjustment when the
    Відповідь
    (D)
    final image is at infinity
  • 23
    Which of the following electromagnetic waves is least energetic?
    Відповідь
    (A)
    Infra-red rays
  • 24
    Steel is more suitable for permanent magnet than iron because the former
    Відповідь
    (D)
    retains magnetism more than iron
  • 25
    Four cells each of e.m.f 1.5V and internal resistance of 4Ω are connected in parallel. What is the effective e.m.f. and internal resistance of the combination?
    Відповідь
    (D)
    1.5V, 1Ω
  • 26
    A 3000W electric cooker is to be used on a 200V mains circuit. Which of the fuses below can be used safely with the cooker?
    Відповідь
    (D)
    20A
  • 27
    A galvanometer has a resistance of 5Ω. By using a shunt wire of resistance 0.05Ω, the galvanometer could be converted to an ammeter capable of reading 2Amp. What is the current through the galvanometer?
    Відповідь
    (C)
    20mA
  • 28
    In fleming's right-hand rule, the thumb, the forefinger and the middle finger if held mutually at right angles represent respectively, the
    Відповідь
    (A)
    motion, the field and the induced current
  • 29
    At what frequency would a 10H inductor have a reactance of 2000Ω?
    Відповідь
    (C)
    100/πHz
  • 30
    The core of an efficient transformer should consist of laminated pieces of metal in order to
    Відповідь
    (D)
    reduce the heat produced by reducing the eddy current
  • 31
    Gamma rays are produced when
    Відповідь
    (B)
    energy changes occur within the nucleus of atoms
  • 32
    What is the speed of a particle of mass 10-27kg whose wavelength is 10-8m.

    [h = 6.63 x 10-34Js]
    Відповідь
    (B)
    66.30ms-1
  • 33
    in a series R-L-C circuit at resonance, the voltages across the resistor and the inductor are 30V and 40V respectively, what is the voltage across the capacitor?
    Відповідь
    (B)
    40V
  • 34
    In the Rutherford scattering experiment, a beam of alpha particles was fired at a thin gold film with some of the particles being considerably deflected. This shows that
    Відповідь
    (B)
    the gold nucleus is positively charged and is concentrated in a tiny volume
  • 35
    2311Na + Proton → pqX + alpha particle
    What are the values of p and q respectively in the equation above?
    Відповідь
    (C)
    20 and 10
  • 36
    A semiconductor diode is used in rectifying alternating current into direct current mainly because it
    Відповідь
    (D)
    allows current to flow only in one direction
  • 37
    if ∆x is the uncertainty in the measurement of the position of a particle along the x-axis and ∆Px is the uncertainty in the measurement of the linear momentum along the x-axis, then the uncertainty principle relation is given as
    Відповідь
    (A)
    ∆x ∆Px ≥ h
  • 38
    If ∆x is the uncertainty in the measurement of the position of a particle along the x-axis and ∆Pa is the uncertainty in the measurement of the linear momentum along the x-axis, then the uncertainty principle relation is given as
    Відповідь
    (A)
    ∆x ∆Px ≥ h
  • 39
    The diagram above shows the velocity-time graph of a vehicle. Its acceleration and retardation respectively are
    Відповідь
    (C)
    4.0 ms-2, 2.0 ms-2
  • 40

    The figure above represents a frictionless pulley system in which a weight W is in equilibrium with a weight of 40N. Find the value of W

    Відповідь
    (D)
    80.0N
  • 41
    The diagram above shows a solid figure with base PQ and center of gravity G on a inclined plane. Which of the following statements is correct
    Відповідь
    (A)
    The solid will fall over if the vertical line through G lies outside the base
  • 42
    The diagram above shows a lift pump with valves at P and Q. During a downward stroke of the piston
    Відповідь
    (B)
    P is open while Q is closed
  • 43
    In the J-tube above, Y and X are on the same horizontal level and 30cm3 of air is trapped above Y when the atmospheric pressure is 75cm Hg, calculate the volume of air trapped above Y when 15cm Hg is now poured into the limb above X
    Відповідь
    (B)
    25 cm3
  • 44
    The diagram above represents a transverse electromagnetic wave travelling with speed 3.0 x 108ms-1. What is the frequency of the wave.
    Відповідь
    (D)
    3.0 x 109Hz
  • 45
    The diagram above shows the prism arrangement in a
    Відповідь
    (C)
    periscope