Light of wavelength $$550$$ $$nm$$ falls normally on a slit of width $$22.0 \times {10^{ - 5}}$$ $$cm.$$ The angular position of the second minima from the central maximum will (in radians) :

A force of $$40$$ $$N$$ acts on a point $$B$$ at the end of an $$L$$-shaped object, as shown in the figure. The angle $$\theta $$ that will produce maximum moment of the force about point $$A$$ is given by :

A body of mass m is moving in a circular orbit of radius R about a planet of mass M. At some instant, it splits into two equal masses. The first mass moves in a circular orbit of radius $${R \over 2},$$ and the other mass, in a circular orbit of radius $${3R \over 2}$$. The difference between the final and initial total energies is :

A charge $$Q$$ is placed at a distance $$a/2$$ above the center of the square surface of edge a as shown in the figure.


The electric flux through the square surface is