When current is flowing through a car’s rear defroster (Exercise 33), the voltage at each end of the metal strips is different. Which end of each strip has the higher voltage, the one through which current enters the strip or the one through which current leaves, and what causes the voltage drop?

The voltage released because the charges in the current dropped electric potential energy; this energy loss occured due to the resistance of the metal strips.

Explanation:

Current flows from huge voltage (high potential) to base voltage (low potential). So the end of the strip wherever the current goes at a higher voltage than the end of the strip where the current leaves. The voltage released because the charges in the current dropped electric potential energy; this energy loss occured due to the resistance of the metal strips. The electric potential energy converted into thermal energy, heating the strips.