The power supply used in a solar energy storage system contains 1200 rechargeable cells, each of electromotive force (e.m.f.) 2.0 V2.0\text{ V}2.0 V.
The cells are contained in packs in which all the cells are in series with each other. The e.m.f. of each pack is 80 V80\text{ V}80 V.
Calculate the number of packs in the power supply.
When in use, each pack supplies a current of 4.5 A4.5\text{ A}4.5 A.
Calculate the rate at which each cell is transferring chemical energy to electrical energy.
The packs are connected in parallel to supply a large total current to the energy storage system. Explain why it is necessary to use thick wires to carry this current.
136 exam-style questions on CIE IGCSE Physics 4.3 Electric circuits, covering 4.3.1a Circuit diagrams and circuit components, 4.3.2a Series circuits, 4.3.2b Parallel circuits, 4.3.2c Current and potential difference in circuits, 4.3.2d Combined resistance of resistors in parallel, and 4.3.3 Action and use of circuit components. Each one has a worked solution and a mark scheme showing where the marks go.