Question

Dielectrics play an important role in design of capacitors. The molecules of a dielectric may be polar or non-polar. When a dielectric slab is placed in an external electric field, opposite charges appear on the two surfaces of the slab perpendicular to electric field. Due to this an electric field is established inside the dielectric. The capacitance of a capacitor is determined by the dielectric constant of the material that fills the space between the plates. Consequently, the energy storage capacity of a capacitor is also affected. Like resistors, capacitors can also be arranged in series and/or parallel.

Which of the following statements about dielectrics is correct?

विकल्प

• A polar dielectric has a net dipole moment in absence of an external electric field which gets modified due to the induced dipoles.

• The net dipole moments of induced dipoles is along the direction of the applied electric field.

• Dielectrics contain free charges.

• The electric field produced due to induced surface charges inside a dielectric is along the external electric field.

Answer 1

The net dipole moments of induced dipoles is along the direction of the applied electric field.

Explanation:

The dipole moment ranges from negative to positive charge. When an external electric field is supplied, the induced dipoles' net dipole moments align with it.