Question

What is the effect of temperature on dielectric constant?

Answer 1

Hint: In order to answer this problem let us first get some idea about the dielectric. A material that is dielectric, insulating, or a poor conductor of electric current. When dielectrics are exposed to an electric field, they produce almost no current because, unlike metals, they do not contain any loosely bound, or free, electrons that could travel through the material. Electric polarisation, on the other hand, occurs.

Complete step-by-step solution:
Positive charges in the dielectric are displaced minutely in the direction of the electric field, whereas negative charges are displaced minutely in the opposite direction. The electric field within the dielectric is reduced by this tiny charge separation, or polarisation.
The dielectric constant is defined as the ratio of the material's electric permeability to that of empty space (i.e., vacuum), and its value can be calculated using a simplified capacitor model.
$\kappa = \dfrac{E}{{{E_0}}}$
$k = $ dielectric constant
 $E = $Permittivity of the substance
${E_ \circ } = $Permittivity of a vacuum
Temperature has an inverse relationship with the dielectric constant. The dielectric constant lowers as the temperature rises.
$k \propto \dfrac{1}{T}$

Note: Dielectrics in capacitors serve three purposes: they keep the conducting plates from touching, allowing for smaller plate separations and thus higher capacitances; they increase the effective capacitance by reducing the electric field strength, they enhance the effective capacitance by reducing the electric field intensity, which means you obtain the same charge at a lower voltage, which means you get the same charge at a lower voltage.