Some of the power that is fed into a transmission line is lost because of its resistance. This effect is called "ohmic" or "resistive" loss (see ohmic heating). At high frequencies, another effect called "dielectric loss" becomes significant, adding to the losses caused by resistance. Dielectric loss is caused when the insulating material inside the transmission line absorbs energy from the alternating electric field and converts it to heat (see dielectric heating). The transmission line is modelled with a resistance (R) and inductance (L) in series with a capacitance (C) and conductance (G) in parallel. The resistance and conductance contribute to the loss in a transmission line.