Optics Question 38
Question: Assertion : An empty test tube dipped into water in a beaker appears silver, when viewed from a suitable direction. Reason : Due to refraction of light, the substance in water appears silvery.
Options:
A) If both assertion and reason are true and the reason is the correct explanation of the assertion.
B) If both assertion and reason are true but reason is not the correct explanation of the assertion.
C) If assertion is true but reason is false.
D) If the assertion and reason both are false.
E) If assertion is false but reason is true.
Show Answer
Answer:
Correct Answer: C
Solution:
The ray of light incident on the water air interface suffers total internal reflections, in that case the angle of incidence is greater than the critical angle.
Therefore, if the tube is viewed from suitable direction (so that the angle of incidence is greater than the critical angle), the rays of light incident on the tube undergoes total internal reflection. As a result, the test tube appears as highly polished i.e. silvery.
