JAMB Physics: practice questions.

Question 1 · Change of state

A cooling curve for molten candle wax shows the temperature falling steeply, then staying constant at 55 °C for several minutes, then falling again. The flat portion shows that

1. A.the wax is boiling
2. B.the wax has stopped losing heat
3. C.the thermometer has stopped working
4. D.the wax is solidifying and releasing latent heat of fusion

eZine practice question (original, teacher-reviewed)

Question 2 · Friction

For small spheres falling through the same viscous liquid, the terminal velocity is proportional to the square of the radius. If the radius of a sphere is doubled, its terminal velocity becomes

1. A.4 times as large
2. B.8 times as large
3. C.half as large
4. D.2 times as large

eZine practice question (original, teacher-reviewed)

Question 3 · Quantity of heat

According to Newton's law of cooling, the rate of heat loss from a cup of hot tea in a draughty room is proportional to

1. A.its mass only
2. B.the excess of its temperature over that of the surroundings
3. C.the square of its temperature
4. D.its absolute temperature raised to the fourth power

eZine practice question (original, teacher-reviewed)

Question 4 · Quantity of heat

How much heat is needed to raise the temperature of 2 kg of water from 25 °C to 75 °C? (specific heat capacity of water = 4200 J kg^-1 K^-1)

1. A.4.2 × 10^5 J
2. B.2.1 × 10^5 J
3. C.6.3 × 10^5 J
4. D.8.4 × 10^3 J

eZine practice question (original, teacher-reviewed)

Question 5 · Temperature and its measurement

Temperature is best described as

1. A.the heat lost by a body per second
2. B.the degree of hotness of a body, which decides the direction of heat flow
3. C.the energy needed to melt a body
4. D.the total quantity of heat in a body

eZine practice question (original, teacher-reviewed)

Question 6 · Thermal expansion

The linear expansivity of brass is 1.9 × 10^-5 K^-1. Its cubic (volume) expansivity is

1. A.3.8 × 10^-5 K^-1
2. B.5.7 × 10^-5 K^-1
3. C.1.9 × 10^-5 K^-1
4. D.6.3 × 10^-6 K^-1

eZine practice question (original, teacher-reviewed)

Question 7 · Refraction of light through plane and curved surfaces

A ray of light passes from air into a glass block. The angle of incidence is 45° and the angle of refraction is 30°. The refractive index of the glass is

1. A.0.71
2. B.1.50
3. C.1.22
4. D.1.41

eZine practice question (original, teacher-reviewed)

Question 8 · Magnets and magnetic fields

Which of the following will NOT demagnetise a bar magnet?

1. A.Hammering it while it lies east–west
2. B.Withdrawing it slowly from a solenoid carrying alternating current
3. C.Heating it strongly
4. D.Stroking it repeatedly in one direction with the N-pole of another magnet

eZine practice question (original, teacher-reviewed)

Question 9 · Scalars and vectors

Two forces of 6 N and 8 N act on a body at right angles to each other. The magnitude of their resultant is

1. A.14 N
2. B.2 N
3. C.48 N
4. D.10 N

eZine practice question (original, teacher-reviewed)

Question 10 · Elementary modern physics

A major limitation of Rutherford's nuclear model, which Bohr's theory addressed, was that

1. A.it assumed the atom was a solid sphere
2. B.it could not explain alpha-particle scattering
3. C.an orbiting electron should radiate energy continuously and spiral into the nucleus
4. D.it could not explain the existence of the nucleus

eZine practice question (original, teacher-reviewed)

Question 11 · Refraction of light through plane and curved surfaces

For a converging lens, an object is 9 cm from the principal focus on one side and its real image is 16 cm from the principal focus on the other side. The focal length of the lens is

1. A.12 cm
2. B.12.5 cm
3. C.144 cm
4. D.25 cm

eZine practice question (original, teacher-reviewed)

Question 12 · Conduction of electricity through liquids and gases

A jeweller in Benin City wants to silver-plate a brass spoon. The correct arrangement is

1. A.spoon as cathode, pure silver as anode, a silver salt solution as electrolyte
2. B.spoon as cathode, carbon as anode, sugar solution as electrolyte
3. C.spoon as anode, carbon as cathode, dilute acid as electrolyte
4. D.spoon as anode, silver as cathode, a silver salt solution as electrolyte

eZine practice question (original, teacher-reviewed)