Generating electricity

Abstract

After this chapter you should

• know that an e.m.f. is induced in a wire if it sweeps across a magnetic field

• know that a rotating armature coil in a motor experiences an e.m.f.

• be able to draw a diagram and explain how an alternating e.m.f. may be induced

• be able to explain the construction of a transformer

• understand step up and step down transformers

• know why the National Grid uses a high voltage supply system

• know how data can be stored on magnetic tape and retrieved.