A parallel beam of monochromatic light falls normally on a single narrow slit. The angular width of the central maximum in the resulting diffraction pattern

Light waves from two coherent sources arrive at two points on a screen with path difference of zero and $$\frac{\lambda^{\prime}}{2}$$. The ratio of intensities at the points is $$\left(\cos 0^{\circ}=1, \cos \pi=-1\right)$$

A person is observing a bacteria through a compound microscope. For better observation and to improve its resolving power he should

In Young's double slit experiment the separation between the slits is doubled without changing other setting of the experiment to obtain same fringe width, the distance 'D' of the screen from slit should be made