There is leakage current due to the non-metallic grounding of the circuit; why then does the voltage of this circuit decrease?

Non-metallic grounding leakage in the circuit causes current leakage, which in turn increases the resistance of the circuit. An increase in resistance leads to a decrease in voltage; in other words, a voltage drop occurs. Furthermore, since resistance heat loss is inevitably generated during current transmission, the greater the current leakage, the greater the resistance heat loss, which in turn leads to a decrease in line voltage. .

What is the theory behind current leakage causing an increase in resistance? . An increase in resistance reduces the voltage; what theory is that again? . .

Non-metallic grounding refers to the situation in which one phase of the distribution network is grounded through a series of non-metallic materials such as semiconductive substances or insulating materials, rather than being directly connected to a grounding metal box. As a result, in the case of non-metallic grounding, the phase voltage does not drop to zero immediately, but instead approaches zero. Due to the varying conductivity of non-metallic materials, the voltage difference between the grounded phase and the ungrounded phase in a distribution network also varies. If the conductivity of a non-metallic material is high, the voltage difference will be large; for example, when a circuit is connected to grease or water, the voltage differences are not equal. In faults related to non-metallic grounding, the magnitude of voltage changes in the grounded and ungrounded phases is directly related to the conductivity of the non-metallic material in direct contact with the ground.