Electric Charges and Fields Test - 5

A negative ion is an atom that has gained one or more electrons and formed an ion.

The charge on the rod is shared between the rod and the sphere when they are in contact with each other. However, on grounding the charge will flow to the earth and the charge on the sphere becomes zero.

Since the ebonite rod rubbed with a fur get negatively charged. Divergence increases if an ebonite rod rubbed with fur is brought near the disc of an negatively charged gold leaf electroscope.

Gain or loss of charge in terms of few electrons each carrying very small charge is unobservable at macroscopic level.

Coulomb’s law obeys Newton’s third law as the force developed on one charge due to the other is always equal and opposite to the force developed on the second charge by the first charge.

A polar molecule has charges whose centres do not coincide with each other. Therefore, they have a dipole moment even in the absence of an external electric field. This dipole moment is permanent.

Non-polar molecules develop a dipole moment only in the presence of an electric field. When the field is removed, the dipole moment is lost.

Electric lines of force never intersect each other because at the point of intersection, two tangents can be drawn to the two lines of force. This means two direction of electric field at the point of intersection, which is not possible.