In young's double-slit experiment set up, sources S of wavelength 50 nm illumiantes two slits `S_(1)` and `S_(2)` which act as two coherent sources. The sources S oscillates about its own position according to the equation `y = 0.5 sin pi t`, where y is in nm and t in seconds. The minimum value of time t for which the intensity at point P on the screen exaclty in front of the upper slit becomes minimum is

Answer

(a)`y^(')=-sinpit` (b)`1/(6)s`