JAMB Physics 2009 past questions and answers

The values of x, y and z respectively in the expression M^xL^yT^z for the universal gravitational constant G are

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

I. Diameter of a small ball bearing.
II. Thickness of a piece of paper.
III. Diameter of a measuring cylinder.
IV. Length of a piece of wire.
Which of the above can be measured using a micrometer screw gauge?

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

An aircraft attempts to fly due north at 100 kmh⁻¹. If the wind blows against it from east to west at 60 kmh⁻¹, its resultant velocity is

1. A.117kmh⁻¹, N31°E.
2. B.127kmh⁻¹, N31°E.
3. C.117kmh⁻¹, N31°W.
4. D.127kmh⁻¹, N31°W.

What is the acceleration between two points on a velocity-time graph which has coordinates (10s, 15 ms⁻¹) and (20 s, 35 m s⁻¹)?

1. A.1.75 ms⁻²
2. B.3.50 ms⁻²
3. C.1.00 ms⁻²
4. D.2.00 ms⁻²

A car accelerates uniformly from rest at 4ms⁻². How far will it travel in the fifth complete second?

1. A.100 m
2. B.50 m
3. C.32 m
4. D.18 m

Which of the diagrams below shows the position at which a small ball-bearing is in neutral equilibrium?

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

A body of mass 12 kg travelling at 4.2 ms⁻¹ collides with a second body of mass 18 kg at rest. Calculate their common velocity if the two bodies coalesce after collision.

1. A.1.5 ms⁻¹.
2. B.1.4 ms⁻¹.
3. C.2.1 ms⁻¹.
4. D.1.7 ms⁻¹.

A bullet fired vertically upward from a gun held 2.0 m above the ground reaches its maximum height in 4.0 s. Calculate its initial velocity. [g ≈ 10 ms⁻²]

1. A.10 ms⁻¹.
2. B.8 ms⁻¹.
3. C.40 ms⁻¹.
4. D.20 ms⁻¹.

I. The motion of the tyres of a moving car.
II. The motion of a loaded test tube oscillating vertically.
III. The beating of the heart.
IV. A stone tied to a string and whirled round.
V. The motion of the pistons in a gasoline engine.
Which of the motions above is simple harmonic?

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

If a cage containing a truck of coal weighing 750 kg is raised to a height of 90 m in 1 minute, what is the total power expended? [g ≈ 10 ms⁻²]

1. A.11.50 kW
2. B.12.60 kW
3. C.11.25 kW
4. D.12.10 kW

An object of mass 80 kg is pulled on a horizontal rough ground by a force of 500 N. Find the coefficient of static friction. [g ≈ 10 ms⁻²]

1. A.0.8.
2. B.0.4.
3. C.1.0.
4. D.0.6.

If a heavy barrel is rolled up a plane inclined at 30° to the horizontal, its velocity ratio will be

1. A.3.0.
2. B.3.1.
3. C.3.2.
4. D.2.0.

The terminal velocity of a ball-bearing falling through a viscous fluid is reached when the

1. A.upthrust is equal to the weight of the ball.
2. B.ball accelerates uniformly.
3. C.upthrust is equal to the velocity of the ball.
4. D.velocity is unform.

I. Density of the liquid.
II. Acceleration due to gravity
III. Type of container of the liquid
IV. The constituents of the liquid.
Which of the above conditions will NOT affect the pressure of fluids?

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

The diagram above represents the graph of the force (F) applied in stretching a spiral spring against the corresponding extension(X). The force constant of the spring is

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

If a load of mass 10N stretches a cord by 1.2cm, what is the total work done?

1. A.6.0 × 10⁻²J
2. B.7.6 × 10⁻²J
3. C.1.8 × 10⁻²J
4. D.6.6 × 10⁻²J

A plastic sphere floats in water with 50% of its volume submerged. If it floats in glycerine with 40% of its volume submerged, the density of the glycerine is [density of water = 1000 kgm⁻³]

1. A.1400 kgm⁻³.
2. B.1250 kgm⁻³.
3. C.500 kgm⁻³.
4. D.1000 kgm⁻³.

The thermometer whose reading is indicated by a change in colour of its thermometric property is the

1. A.bi-metallic strip thermometer.
2. B.thermocouple.
3. C.platinum resistance thermometer.
4. D.optical pyrometer.

At 4°C, the volume of a fixed mass of water is

1. A.constant.
2. B.minimum.
3. C.maximum.
4. D.zero.

The pressure of two moles of an ideal gas at a temperature of 27°C and volume 10⁻²m³ is [R = 8.313 J mol⁻¹K⁻¹]

1. A.4.99 × 10⁵ Nm⁻².
2. B.9.80 × 10³ Nm⁻².
3. C.4.98 × 10³ Nm⁻².
4. D.9.80 × 10⁵ Nm⁻².

An electric heater rated 220 V, 1000 W is immersed into a bucket full of water. Calculate the mass of water if the temperature changes from 30°C to 100°C and the current flows for 300 seconds. [specific heat capacity of water = 4200 J kg⁻¹ K⁻¹]

1. A.4.28 kg.
2. B.42.86 kg.
3. C.1.02 kg.
4. D.7.14 kg.

If the pressure of the vapour on top of an enclosed liquid is equal to the atmospheric pressure, what will be the temperature of the liquid enclosed?

1. A.Room temperature
2. B.Boiling point
3. C.Freezing point
4. D.Standard temperature

A heating coil rated 1000 W is used to boil off completely 2 kg of boiling water. The time required to boil off the water is [specific latent heat of vaporization of water = 2.3 × 10⁶ Jkg⁻¹]

1. A.1.15 × 10⁴ s.
2. B.1.15 × 10³ s.
3. C.4.6 × 10⁴ s.
4. D.4.6 × 10³ s.

It is observed that water will wet a clean glass because the

1. A.cohesion of water to glass is stronger than the cohesion of water molecules.
2. B.adhesion of water molecules is weaker than the cohesion of water to glass.
3. C.cohesion of water to glass is weaker than the cohesion of water molecules.
4. D.adhesion of water molecules is stronger than the cohesion of water molecules.

A man standing 2 m from a charcoal fire is warmed mainly by

1. A.convection.
2. B.radiation.
3. C.refraction.
4. D.conduction.

The wave phenomenon demonstrated in the diagram above is

1. A.reflection.
2. B.deflection.
3. C.diffraction.
4. D.refraction.

A progressive wave is represented by y = 10 sin (1000 t − πx/34). Two layers of the wave separated by 153cm have a phase difference of

1. A.270°.
2. B.45°.
3. C.90°.
4. D.180°.

Metal cables are used as telephone wires because

1. A.they are cheap.
2. B.they are sourced locally.
3. C.the speed of sound in them is very low.
4. D.the speed of sound in them is very high

Musical instruments playing the same note can be distinguished from one another owing to the differences in their

1. A.quality.
2. B.pitch.
3. C.intensity.
4. D.loudness.

I. Moon II. Sun III. Street light IV. Stars
Which of the above is a natural source of light?

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

An object is placed 5cm from the pole of a concave mirror. If the focal length of the mirror is 10 cm, what is the image distance?

1. A.10 cm in front of the mirror
2. B.5 cm in front of the mirror
3. C.10 cm behind the mirror
4. D.5 cm behind the mirror

Calculate the position of an object placed in front of a convex mirror having focal length of 12cm such that an image is formed 6cm away from the mirror.

1. A.4.0 cm.
2. B.3.0 cm.
3. C.12.0 cm.
4. D.9.0 cm.

If the refractive index of crown glass is 1.51, its critical angle is

1. A.48.6°.
2. B.22.5°.
3. C.41.5°.
4. D.45.0°.

When light passes through two media x and y of refractive indices 1.51 and 1.33 respectively, the speed of light in

1. A.x is same as in y.
2. B.x and y is same as in vacuum.
3. C.x is higher than in y.
4. D.y is higher than in x.

The ability of the human eye to focus objects on the retina is referred to as the power of

1. A.interference.
2. B.diffraction.
3. C.accommodation.
4. D.superposition.

Which of the following is a secondary colour?

1. A.Blue
2. B.Orange
3. C.Red
4. D.Green

If negative charges are induced on an electroscope and a positively charged rod is brought near the cap of the electroscope, the leaves will

1. A.close up.
2. B.become positively charged.
3. C.become negatively charged.
4. D.open further.

Calculate the e.m.f. of the cell in the above circuit if its internal resistance is negligible.

1. A.12V.
2. B.8V.
3. C.2V.
4. D.36V.

An electric lamp marked 240V, 60W is left to operate for an hour. How much energy is generated by the filament?

1. A.3.86 × 10⁵ J
2. B.3.56 × 10⁵ J
3. C.1.80 × 10⁴ J
4. D.2.16 × 10⁵ J

A band of 500 rectangular loops of wire of area 20 cm by 20 cm, encloses a region of magnetic field which changes from 1.0T to 0.4T within 5 seconds, calculate the induced e.m.f.

1. A.5.60 V.
2. B.24.00 V.
3. C.0.24 V.
4. D.2.40 V.

From the diagram above, if the potential difference across the resistor, capacitor and inductor are 80 V, 110 V and 40 V respectively, the effective potential difference is

1. A.116.3 V.
2. B.50.0 V.
3. C.230.0 V.
4. D.106.3 V.

Cancerous cells can be destroyed by

1. A.ultraviolet rays.
2. B.alpha particles.
3. C.x-rays.
4. D.infrared rays.

If the decay constant of a radioactive substance is 0.231s⁻¹, the half-life is

1. A.3.00s.
2. B.0.12s.
3. C.0.33s.
4. D.1.50s.

A piece of radioactive material contains 10²⁰ atoms. If the half-life of the material is 20 seconds, the number of disintegrations in the first second is

1. A.3.47 × 10¹⁸.
2. B.6.93 × 10²⁰.
3. C.3.47 × 10²⁰.
4. D.6.93 × 10¹⁸.

Thermionic emission is the process whereby

1. A.β-rays are produced.
2. B.holes are produced.
3. C.x-rays are produced.
4. D.electrons leave a hot element.

Which of the following can conduct electricity owing to the presence of free mobile electrons?

1. A.Germanium
2. B.Silicon
3. C.Grapefruit
4. D.Copper

When a pentavalent impurity is added to a pure semiconductor, it becomes

1. A.a p-type semiconductor.
2. B.an n-type semiconductor.
3. C.an insulator.
4. D.an intrinsic semiconductor.