Optics Question 13
Question: Assertion : If a plane glass slab is placed on the letters of different colours all the letters appear to be raised up to the same height. Reason : Different colours have different wavelengths.
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: E
Solution:
Apparent shift for different coloured letter is $ d=h( 1-\frac{1}{\mu } ) $
Therefore $ {\lambda _{R}}>{\lambda _{V}} $ so $ {\mu _{R}}<{\mu _{V}} $ .
Hence $ d _{R}<d _{V} $ i.e. red coloured letter raised least.
