Assertion : The electric field due to a dipole on its axis line at a distance $$r$$ is $$E$$. Then, electric field due to the same dipole on the equatorial line and at the same distance will be $$E / 2$$.
Reason : Electric field due to dipole varies inversely as the square of the distance.
Assertion : A potentiometer is preferred over that of a voltmeter for measurement of emf of a cell.
Reason : Potentiometer does not draw any current from the cell.
Assertion : The magnetism of magnet is due to the spin motion of electrons.
Reason : Dipole moment of electron is smaller than that due to orbit motion around nucleus.
Assertion : The mirror used in search lights are parabolic and not concave spherical.
Reason : In concave spherical mirror, the image formed is always virtual.