- Types of Transformer
- characteristics of primary and secondary coils
How is the e.m.f. across primary and secondary coils of a transformer related with the number of turns of the coil in them?
The adjacent diagram shows a coil would around a soft iron bar XY. (a) State the polarity at the end X and Y as the switch is pressed. (b) Suggest one way increasing the strength of electromagnet so formed.
The following diagram in Fig. 10.44 shows a coil X connected to a sensitive centre –zero galvanometer G and a coil P connected to a battery through a switch S.
(a) Describe the observation when the switch S is (i) closed suddenly, (ii) then kept closed, (iii) finally opened.
(b) Name and state the law which explains the above observations.
A transformer is designed to work from a 240 V a.c. mains and to give a supply of 8 V to ring
a house–bell. The primary coil has 4800 turns. How many turns will be in the secondary coil?