A lemon kept in water in a glass tumbler appears to be larger than its actual size. It is because of
- A.reflection of light
- B.scattering of light
- C.refraction of light
- D.polarization of light
Correct answer
Explanation
The correct answer is C, refraction of light. The lemon looks bigger because light from it bends as it passes from water through the curved glass into air.
A round glass tumbler filled with water behaves like a convex lens. Light rays from the lemon are refracted at the curved surface as they leave the denser medium, and they spread out as if they came from a larger object placed nearer, so the eye sees a magnified, virtual image. The same refraction makes a pool look shallower than it is and a straw look bent in a glass of water.
A is wrong because reflection sends light back into the same medium; it forms images in mirrors, not enlarged images through water.
B is wrong because scattering explains the blue sky and the red sunset, not magnification.
D is wrong because polarisation is about the direction in which light waves vibrate and does not change the apparent size of an object.
Exam tip: bent straw, shallow pool, twinkling stars and the enlarged lemon are all examples of refraction.
Practice Questions
View allWhich one of the following is the purest form of Carbon ?
- A.Charcoal
- B.Coke
- C.Fullerene
- D.Carbon black
Show answer
Fullerenes are made of carbon atoms alone, with no surface to trap other substances, so they are counted as the purest form of carbon.
Read the full explanation →A planet has a mass M₁ and radius R₁. The value of acceleration due to gravity on its surface is g₁. There is another planet 2, whose mass and radius both are two times that of the first planet. Which one of the following is the acceleration due to gravity on the surface of planet 2?
- A.g₁
- B.2g₁
- C.g₁/2
- D.g₁/4
Show answer
Surface gravity is g = GM/R², so doubling the mass doubles g while doubling the radius divides it by four, leaving g₁ × 2/4 = g₁/2.
Read the full explanation →Which one of the following is the major constituent of biogas ?
- A.Carbon dioxide
- B.Nitrous oxide
- C.Methane
- D.Oxygen
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Methane makes up the largest share of biogas, usually about 55 to 75 per cent, and it is the gas that burns.
Read the full explanation →Which one of the following conclusions could not be derived from Rutherford's α-particle scattering experiment?
- A.Most of the space in the atom is empty.
- B.The radius of the atom is about 10⁵ times the radius of the nucleus.
- C.Electrons move in a circular path of fixed energy called orbits.
- D.Nearly all the mass of the atom resides in the nucleus.
Show answer
. Orbits of fixed energy were proposed by Niels Bohr in 1913; Rutherford's experiment said nothing about the energy of electrons.
Read the full explanation →Which one of the following is the mechanism of action of oral contraceptive pills?
- A.They kill the egg.
- B.They kill the sperm.
- C.They kill the zygote.
- D.They inhibit the release of egg.
Show answer
. Oral contraceptive pills prevent pregnancy mainly by stopping the ovary from releasing an egg.
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