WAEC Physics 2022 Theory — Question 10

Model answer

(a)(ii) The volt is defined as the potential difference between two points in a conductor when one joule of work is done in moving one coulomb of charge (electricity) between the two points. (c) Wood is not suitable for use as the core of transformers because it is not a magnetic material and this would not provide magnetic coupling between coils for electromagnetic induction. The main purpose of using a core in a transformer is to carry the flux; magnetic materials (e.g. iron/steel) are used in transformer cores because of their tendency to carry or link the flux in the primary and secondary windings. A wooden core cannot provide this linkage. (d) Applications of cathode ray tube: For studying alternating current wave form; for measuring frequency/voltage/reactance/power factor and resistance of an electronic device; used to monitor signals/check FM/AM characteristics.