Question

Statement I When light travels from a rarer to a denser medium, the speed decreases but energy of the wave remains same.
Statement II Intensity of light wave is directly proportional to the square of the amplitude of the wave.

• A. Both Statement I and Statement II are correct and Statement II is the correct explanation of statement I.
• B. Both Statement I and Statement II are correct but Statement II is not the correct explanation of Statement I.
• C. Statement I is correct but Statement II is incorrect.
• D. Statement I is incorrect but Statement II is correct.

Answer 1

Answer: (B)

$\mu=\frac{c}{v}$
Hence, the speed of light decreases in denser medium. Energy carried by a wave depends on the amplitude of the wave, not on the speed of wave propagation. Energy remains same.
Also, intensity of wave $\propto(\text { amplitude })^{2}$ or $I \propto A^{2}$