Magnetic keepers are used to protect magnets from :
A). Earth's magnetic field
B). Effect of other magnets
C). Self-demagnetization
D). Demagnetization due to heating
Self-demagnetization
Magnetic keepers are soft iron bars placed at either end of the pair of magnets. It is used to avoid self-demagnetisation of magnets.
3. Which instrument is used for photographing the Sun?
4. Tape recorder should not be kept near one of the following things :
6. In a filament type light bulb most of the electric power consumed appears as
7. It is easy to burst a gas-filled balloon with a needle than with a nail. It is because
8. Which one of the following is the most stable ecosystem?
9. In nuclear reactor heavy water is used as
10. A piece of wood is held under water. The upthrust on it will be: