How much energy is given to each coulomb of charge that flows through a 1.5-V battery?
Solution 27RQ STEP 1: The electrostatic potential energy is defined as, “the amount of work has to be done on a charge to bring it from infinity to a certain distance R from the source charge”. It’s unit is jules or volts × coulomb. 1 Qq U = 40 r ----------------(1) The electrostatic potential is defined as the electrostatic potential energy per unit charge. It’s unit is volts. V = Q --------------------(2) 40 r STEP 2: The potential difference between the two ends of the battery is given as 1.5 volts. From equation (1) and (2), U = V q = 1.5 volts × q ---------------(3) So, this is the energy required to move the total charge. Per unit charge the energy requirement is, U/q = V q/q = V = 1.5 jules. CONCLUSION: Each coulomb of charge requires 1.5 jules of energy or 1.5 jules/coulomb is required.
