2020 - JAMB Physics Past Questions and Answers - page 3
Two mirrors of the same length are arranges as show in the diagram. A ray of light NO strikes the system at O and emerges along PQ. The emergent ray has been deviated through
220\(^o\)
200\(^o\)
210\(^o\)
180\(^o\)
A magnetic needle is suspended first at the earth's north magnetic pole and then at a point on the magnetic equator. The respective angles between the needle and the horizontal are
0\(^o\) and 0\(^o\)
60\(^o\) and 60\(^o\)
90\(^o\) and 90\(^o\)
90\(^o\) and 0\(^o\)
A hydrometer is an instrument for measuring the
a depth of water of water in a vessel
relative density of a liquid by the method of flotation
relative density of a liquid by finding the apparent loss in weight
relative humidity of the air
Consider the three forces acting at O and in equilibrium as shown in the figure. Which of the following equations is/are CORRECT?
I. P\(_1\) sin \(\theta_1\) = p\(_1\) cos \(\theta_2\)
II. P\(_3\) = P\(_1\) cos \(\theta_4\) + P\(_2 cos_2\)
III. P\(_1 \sin \theta_1 = P_2 \sin \theta_2\)
I only
II only
III only
I, II and III only
The refractive index of a liquid is 1.5. If the velocity of light in a vacuum is 3.0 x 10\(^8ms^{-1}\), the velocity of light in the liquid is
1.5 x 10\(^8ms^{-1}\)
2.0 x 10\(^8ms^{-1}\)
3.0 x 10\(^8ms^{-1}\)
4.5 x 10\(^8ms^{-1}\)
A ship travelling towards a cliff receives the echo of its whistle receives the echo of its whistle after 3.5 seconds. If the speed of sound in air under the prevailing conditions is 250ms\(^{-1}\), how much closer is the ship to the cliff?
10m
A. 350m
175m
125m
Which of the following statements about defects of vision is/are CORRECT?
I. For a long sighted person, close objects appear blurred
II. For a short sighted person, distant objects appear blurred
III. Short sight is corrected by using a pair of converging lenses
I only
II only
I and II only
II and III only
Which of the following conditions are necessary and sufficient for total internal reflection to take place at the boundary between two optical media?
I. Light is passing from optical denser medium to optically less dense medium
II. Light is passing from optically less dense medium to optically denser medium to optically denser medium
III. Angle of incidence is greater
IV. Angle of incidence is lesser
I and II only
II only III only
III and IV only
I and III only
The linear expansivity of brass is 2 x 10\(^{-5}\) \(^oC^{-1}\). If the volume of piece of brass is 2 x 10cm\(^3\) at 0\(^o\)C. What will be its volume at 100\(^o\)C?
10.06cm\(^3\)
10.04 cm\(^3\)
10.02 cm\(^3\)
10.06 cm\(^3\)
The lower and upper fixed points marked on a Mercury-in-glass thermometer are 210mm above the lower fixed point in a room. What is the temperature of the room in degrees Celsius?
55.3\(^o\)C
30.43\(^o\)C
49.0\(^o\)C
16.43\(^o\)C
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