Physics
Answer
Faraday formulated the following two laws of electromagnetic induction —
- Whenever there is a change in magnetic flux linked with a coil, an e.m.f. is induced. The e.m.f. induced lasts so long there is a change in the magnetic flux linked with the coil.
- The magnitude of e.m.f. induced is directly proportional to the rate of change of magnetic flux linked with the coil. If magnetic flux changes at a constant rate, a steady e.m.f. is produced.
Related Questions
Complete the following sentences —
(i) In a step up transformer, the number of turns in the primary are ….. than the number of turns in the secondary.
(ii) The transformer is used in ………….. current circuits.
(iii) In a transformer, the frequency of a.c. voltage ……… (increase / decreases / remains same)
Name the material of the core in (a) an electric bell, (b) electromagnet, (c) a d.c. motor, (d) an a.c. generator, and (e) a transformer.
State two factor on which the magnitude of induced e.m.f in a coil depend.
(a) How would you demonstrate that a momentary current can be obtained by the suitable use of a magnet, a coil of wire and a galvanometer?
(b) What is the source of energy associated with the current obtained in part (a)?