Short notes
Objective questions (Answers are given below)
- Permanent magnets are normally made of
(a) aluminium (b) wrought iron
(c) cast iron (d) alnico alloys - A coil of 1000 turns is wound on a core.
A current of 1 A flowing through the coil
creates a core flux of 1 mWb. The energy
stored in the magnetic field is
(a) 0.25 J (b) 0.5 J
(c) 1 J (d) 2 J
(ESE 2003)