Paper: CSIR-NET June 2015 · Subject: Physical Chemistry · Chapter: Chemical Kinetics · Topic: Chemical Kinetics – General · Marks: 2 · Difficulty: Medium
The intensity of a light beam decreases by 50\% when it passes through a sample of 1.0 cm path length. The percentage of transmission of the light passing through the same sample, but of 3.0 cm path length, would be
(a)50.0
(b)25.0
(c)16.67
(d)12.5
Answer
Answer: D ✓ checked by 4AB · confidence high
The source book printed no answer; this one was worked out and checked — see the explanation.
Explanation
Transmittance falls geometrically with path length: T = 0.5³ = 0.125 = 12.5 %.