Temporary and Permanent Magnets

Q. A permanent magnet cannot be changed into a material with no magnetic properties.

1. True
2. False

Q. Lava from volcanoes is one of the probable reason for existence of permanent magnets.

1. False
2. True

Q. Permanent magnets are formed because of heating effect of electricity.

1. True
2. False

Q. Lightning is not a probable cause for formation of permanent magnets.

1. True
2. False

Q. With the help of a metal can be turned into a magnet, temporarily.

1. electricity
2. heating
3. pressing
4. non-metal

Q. Name the alloy which is mainly used for making permanent magnet.

Q. Write two characteristics of a material to constructes a permanent magnet. Give two examples of such materials.

Q. Steel is used for making ............... magnets.

1. permanent
2. right angles
3. electromagnet
4. anticlockwise

Q. When a powerful magnet is held near a piece of soft iron, the latter changes to magnet on account of the phenomenon of :

1. magnetic induction
2. magnetic conduction
3. magnetic attraction
4. none of the above

Q. By removing a permanent magnet, the induced magnetic field is:

1. finished just after.
2. not finished for a long time.
3. finished after some time.
4. not charged.