A device raises the electric potential of charges in two successive stages.
(i) First, 4.0×1020 electrons are moved through a potential difference of 15V. Calculate the work done in this step.
(ii) Next, a positive charge Q is moved through a potential difference of 25V, requiring an additional 500J of work. Determine the magnitude of Q.
(iii) Using your results from parts (i) and (ii), compute the percentage contribution of the electron transfer to the total energy supplied in both steps combined.