Physics 2005 Jamb Examination
Question 21
Diffusion is the process by which molecules of different substances intermingle due to their random motion.
Capillarity and surface tension are properties of liquids, while osmosis is the movement of solvent molecules across a semi-permeable membrane.
Correct option: D (diffusion).
Not clear enough?
Question 22
II. Sensibility
III. High thermal capacity
IV. High accuracy
The qualities of a good thermometer include?
A good thermometer should have:
- Reproducibility (gives the same reading repeatedly)
- Sensibility (responds quickly to temperature change)
- High accuracy (provides correct readings)
A high thermal capacity is undesirable since it slows response.
Correct option: A (I, II and IV only).
Not clear enough?
Question 23
Evaporation is the slow, spontaneous escape of molecules from the surface of a liquid at all temperatures.
Boiling occurs at a fixed temperature with bubble formation. Sublimation is solid ↔ gas change, while regelation is melting under pressure.
Correct option: D (evaporation).
Not clear enough?
Question 24
II. Boiling
III. Refraction
IV. Conduction
Which combination of the above is evidence of the molecular nature of matter?
Changes of state (melting, boiling) and heat transfer by conduction are all explained using the motion of molecules.
Refraction is a wave property of light, not related to molecular motion.
Correct option: B (I, II and IV only).
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Question 25
When hot water is poured into a thick glass, the inner layers heat and expand faster than the outer layers. The stress due to uneven expansion causes the thick glass to crack.
Correct option: D (uneven expansion of glass).
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Question 26
Satellites communicate with ground stations using radio waves (microwaves, a subset of radio waves) because they travel long distances through the atmosphere with little absorption.
Correct option: C (radio wave).
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Question 27
Power = Voltage × Current → Current = P/V = 2000 / 250 = 8 A.
Fuse rating should be slightly above the working current, hence 8 A is correct.
Correct option: B (8 A).
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Question 28
Magnets always exist as dipoles, meaning each magnet has both a north and a south pole. Cutting a magnet results in smaller dipoles, not isolated poles.
Correct option: C (magnetic dipole).
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Question 29
A car battery rated 45 A·h is charged with a charger whose rating is 2.5 A. How long will it take to charge the battery full?
Charging time = Capacity / Current = 45 / 2.5 = 18 h ideally.
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Question 30
Electric field intensity E = F/q = 0.4 / (1.0 × 10-10) = 4.0 × 109 N/C.
Correct option: D (4.0 × 109 N C-1).
Not clear enough?
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