Given below are two statements : In the light of the above statements, choose the correct answer from the options given below :
- Both Statement I and Statement II are true
- Statement I is true but Statement II is false
- Statement I is false but Statement II is true
- Both Statement I and Statement II are false
Answer
(3) Statement I is false but Statement II is true
Solution
Angular separation of fringes in YDSE: = D = d
Statement I: = d does not depend on the slit–screen distance D. Moving the screen away increases the linear fringe width = Dd, but the angular separation stays the same. Statement I is false.
Statement II: , so a source of higher wavelength gives a larger angular separation. Statement II is true.
Answer: (3)