Given below are two statements : In the light of the above statements, choose the most appropriate answer from the options given below :
- Both Statement I and Statement II are correct
- Statement I is correct but Statement II is incorrect
- Both Statement I and Statement II are incorrect
- Statement I is incorrect but Statement II is correct
Answer
(2) Statement I is correct but Statement II is incorrect
Solution
Statement I: E = h [h] = [E][ ] = [ ML2T-2][ T-1] = [ ML2T-1]
Angular momentum L = mvr [L] = [M][ LT-1][L] = [ ML2T-1]
Same dimensions. Correct.
Statement II: As per NCERT (Bohr's second postulate), the electron revolves only in those orbits for which the angular momentum is an integral multiple of h2 , i.e. mvr = nh2 — not an integral multiple of h. Incorrect.
Answer: (2)