JAMB Physics 2014 past questions and answers

A quantity which requires magnitude and direction to be specified is

1. A.distance.
2. B.displacement.
3. C.mass.
4. D.temperature.

I. Electrical potential II. Torque III. Kinetic energy IV. Momentum
Which of the quantities listed above are vectors?

1. A.I and II.
2. B.I and III.
3. C.II and III.
4. D.II and IV.

Which type of motion do the wheels of a moving car undergo?

1. A.Random and translational motion.
2. B.Rotational and oscillatory motion.
3. C.Translational and rotational motion.
4. D.Vibratory and translational motion.

From the diagram above, the region of zero acceleration is

1. A.MN.
2. B.NS.
3. C.SP.
4. D.PQ.

A car accelerates uniformly from rest at 3ms⁻², its velocity after travelling a distance of 24m is

1. A.144 ms⁻¹.
2. B.72 ms⁻¹.
3. C.36 ms⁻¹.
4. D.12 ms⁻¹.

Calculate the escape velocity of a satellite launched from the earth's surface if the radius of the earth is 6.4 × 10⁶m. [g=10 ms⁻²]

1. A.4.2 kms⁻¹.
2. B.4.0 kms⁻¹.
3. C.11.3 kms⁻¹.
4. D.25.3 kms⁻¹.

An object of weight 80kg on earth is taken to a planet where the acceleration due to gravity is one-third of its value on earth. The weight of the object on the planet is [g=10 ms⁻²]

1. A.12 N.
2. B.27 N.
3. C.36 N.
4. D.48 N.

One of the conditions necessary for an object to be in equilibrium when acted upon by a number of parallel forces is that the vector sum of the forces is

1. A.zero.
2. B.negative.
3. C.positive.
4. D.average.

What happens when three coplanar non-parallel forces are in equilibrium?

1. A.They are represented in magnitude only.
2. B.They are represented in direction only.
3. C.Their lines of action meet at a point.
4. D.Their lines of action are parallel.

An object of mass 20kg is released from a height of 10m above the ground level. The kinetic energy of the object just before it hits the ground is [g=10ms⁻²]

1. A.4 000 J.
2. B.2 000 J.
3. C.500 J.
4. D.200 J.

The energy in the nucleus of atoms produce heat which can be used to generate

1. A.mechanical energy.
2. B.electrical energy.
3. C.potential energy.
4. D.kinetic energy.

A machine whose efficiency is 75% is used to lift a load of 1000N. Calculate the effort put in to the machine if it has a velocity ratio of 4.

1. A.233.33 N.
2. B.333.33 N.
3. C.334.33 N.
4. D.343.32 N.

A wheel and axle is used to raise a load whose weight is 800 N when an effort of 250 N is applied. If the radii of the wheel and axle are 800 mm and 200 mm respectively, the efficiency of the machine is

1. A.80%.
2. B.85%.
3. C.87%.
4. D.90%.

A force of 500N is applied to a steel wire of cross-sectional area 0.2m². the tensile stress is

1. A.1.0 × 10²Nm⁻²
2. B.1.0 × 10³Nm⁻²
3. C.2.5 × 10³Nm⁻²
4. D.2.5 × 10⁴Nm⁻²

From the diagram above, the point that represents the elastic limit is

1. A.Q.
2. B.R.
3. C.S.
4. D.T.

A glass bottle of initial volume 2 × 10⁴cm³ is heated from 20°C to 50°C. If the linear expansivity of glass is 9 × 10⁻⁶K⁻¹, the volume of the bottle at 50°C is

1. A.20 005.4 cm³.
2. B.20 008.1 cm³.
3. C.20 013.5 cm³.
4. D.20 016.2 cm³.

The equation P^aV^bT^c = constant reduces to Charles Law if

1. A.a=1, b=0 and c= −1.
2. B.a=0, b=1 and c=1.
3. C.a=0, b=1 and c= −1.
4. D.a=1, b=1 and c=0.

The quantity of heat needed to raise the temperature of a body by 1K is the body's

1. A.internal energy.
2. B.specific heat capacity.
3. C.latent heat of fusion.
4. D.heat capacity.

The melting point of a substance is equivalent to its

1. A.solidification temperature.
2. B.liquidification temperature.
3. C.solidification pressures.
4. D.vapour pressure.

The temperature at which the water vapour present in the air just sufficient to saturate the air is

1. A.ice point.
2. B.saturation point.
3. C.dew point.
4. D.boiling point.

Heat transfer by convection in a liquid is due to the

1. A.increased vibration of the molecules of the liquid about their mean position.
2. B.variation of density of the liquid.
3. C.expansion of the liquid as it is heated.
4. D.latent heat of vaporization of the liquid.

The distance between two successive crests of a wave is 15 cm and the velocity 300 ms⁻¹. Calculate the frequency.

1. A.4.5 × 10⁵Hz.
2. B.2.0 × 10³Hz.
3. C.4.5 × 10²Hz.
4. D.2.0 × 10²Hz.

A boy receives the echo of his clap reflected by a nearby hill 0.8s later. How far is he from the hill? [speed of sound in air = 340ms⁻¹]

1. A.66 m.
2. B.136 m.
3. C.264 m.
4. D.528 m.

The diagram above shows a stationary wave of wavelength 40 cm in a closed tube. The length L of the resonating air column is

1. A.10 cm.
2. B.20 cm.
3. C.30 cm.
4. D.40 cm.

An object is placed 10 m from a pinhole camera of length 25 cm. Calculate the linear magnification

1. A.2.5 × 10⁻².
2. B.2.5 × 10⁻¹.
3. C.2.5 × 10¹.
4. D.2.5 × 10².

The focal length of a concave mirror is 2.0 cm. If an object is placed 8.0 cm from it, the image is at

1. A.2.0 m.
2. B.2.3 m.
3. C.2.5 m.
4. D.2.7 m.

In a compound microscope, the objective and the eyepiece focal lengths are

1. A.long.
2. B.short.
3. C.the same.
4. D.at infinity.

When a telescope is in normal use, the final image is at

1. A.the focus.
2. B.the radius of curvature.
3. C.the near point.
4. D.infinity.

When a negatively-charged rod is brought near the cap of a charged gold leaf electroscope which has positive charges, the leaf

1. A.collapses.
2. B.collapses and diverges again.
3. C.diverges.
4. D.remains the same.

What charge is stored in a 0.1F capacitor when a 10V supply is connected across it?

1. A.5 C
2. B.4 C
3. C.2 C
4. D.1 C

Calculate the effective capacitance of the circuit above.

1. A.1μf.
2. B.2μf.
3. C.3μf.
4. D.4μf.

The maximum power transfer occurs in a cell when the external resistance is

1. A.the same as the internal resistance of the cell.
2. B.greater than the internal resistance of the cell.
3. C.less than the internal resistance of the cell.
4. D.twice the internal resistance of the cell.

If a metal wire 4 m long and cross-sectional area 0.8 mm² has a resistance of 6Ω, find the resistivity of the wire.

1. A.3.0 × 10⁻⁵Ωm.
2. B.1.2 × 10⁻⁶Ωm.
3. C.3.2 × 10⁻⁶Ωm.
4. D.5.3 × 10⁻⁷Ωm.

A circuit has a resistance of 200Ω. The resistance of the circuit can be reduced to 120Ω when

1. A.an 80Ω resistor is connected to it in series.
2. B.a 150Ω resistor is connected to it in parallel.
3. C.a 240Ω resistor is connected to it in series.
4. D.a 300Ω resistor is connected to it in parallel.

PHCN measures its electrical energy in

1. A.kWh.
2. B.Wh.
3. C.J.
4. D.W.

What is the best method of demagnetizing a steel bar magnet?

1. A.Heating it.
2. B.Rough handling it.
3. C.Solenoid method.
4. D.Hammering.

The magnitude of the angle of dip at the equator is

1. A.0°.
2. B.90°.
3. C.180°.
4. D.360°.

Use the diagram above to answer this question. The diagram above is that of

1. A.a step-up transformer.
2. B.a step-down transformer.
3. C.an auto transformer.
4. D.an oil transformer.

Use the diagram above (the transformer) to answer this question. The electromotive force in the secondary winding is

1. A.increasing.
2. B.reducing.
3. C.stabilizing.
4. D.varying.

What type of reaction is represented by the equation ²₁X + ²₁X → ³₂Y + ¹₀n + energy ?

1. A.Fusion.
2. B.Fission.
3. C.Chain.
4. D.Ionization.

When an atom undergoes a beta decay, the atomic number of the nucleus

1. A.decreases by one.
2. B.increases by one.
3. C.becomes zero.
4. D.remains unchanged.

Calculate the mass of the copper deposited during electrolysis when a current of 4A passes through a copper salt for 2 hours. [ece of copper z=3.3 × 10⁻⁷kgC⁻¹]

1. A.9.5 × 10⁻⁷kg
2. B.9.5 × 10⁻³kg
3. C.2.9 × 10⁻⁴kg
4. D.2.9 × 10⁵kg

Which gas produces a pink coloured light in a discharge tube?

1. A.Argon.
2. B.Air.
3. C.Neon.
4. D.Mercury.

When ²¹⁰₈₂Pb decays to ²⁰⁶₈₀Pb, it emits

1. A.an apha particle.
2. B.one beta particle.
3. C.one alpha and one beta particle.
4. D.two alpha and two beta particles.

In a common emitter configuration, the output voltage is through the

1. A.base.
2. B.collector.
3. C.emitter.
4. D.resistor.

Which of the graphs below shows the characteristics of an I-V transistor?

1. A.A
2. B.B
3. C.C
4. D.D