2a. State Faraday's law of electromagnetic induction. b. Draw a labelled diagram of an induction coil and explain how it works. c. How is the effect of eddy...

Answer Details

a. Faraday's law of electromagnetic induction states that the induced e.m.f. in a circuit is directly proportional to the rate of change of the magnetic flux, or field lines, linking the circuit i.e e ∝ \(\frac{dφ}{\text{dt}}\).

b. See diagram above.  How it works: it has a primary coil of a few turns and a secondary coil of many turns. When the primary circuit is made, a current flows in P. A is then attracted, so breaking the circuit at the contact point. This makes the large magnetic flux in the secondary fall very quickly. A high voltage is then produced at its terminals X and Y, and a spark appears across the air gap as the circuit is made and broken repeatedly.

c. The eddy current can be minimized by laminating the core to reduce energy losses.

d. The spark which produce across the gap of the make and break device is reduced by the capacitor. Thus, it should be included.

e. (i). It is used in the operation of X-ray tubes. (ii). It is used in the generation of high voltages. (iii). It is used in morse radio transmitter.