Tag: let's make a magnet

Questions Related to let's make a magnet

Identify the methods by which a magnet can be demagnetized.

  1. Heating a magnet strongly

  2. Repeated hammering of the magnet

  3. Storing it aligned with the N-S direction

  4. None of these


Correct Option: A,B
Explanation:

Methods by which a magnet can be demagnetized can be given as mentioned below: 
$(1)$ Heating a magnet strongly
$(2)$ Hammering the magnet several times or repeated hammering
$(3)$ By passing an alternating current through the magnet
Hence, the correct options $(A)$ and $(B)$.

A permanent magnet can lose its magnetism with time 

  1. True

  2. False


Correct Option: A
Explanation:
Yes permanent magnet can lose its magnetism in following cases
i) Heating up to certain temperature
ii) Low coercivity and wrong storage.
iii)Energy transfer them by shock.

When the north pole of a bar magnet picks up an iron nail which of the following are induced in the nail ?

  1. North poles

  2. South poles

  3. A north pole and south pole

  4. None of these


Correct Option: B
Explanation:

As the attraction occurs only in between two unlike poles, thus north pole of magnet induces south pole in the nail and north at the other end.

The force with which a magnet attracts objects like iron is called Magnetic force.

  1. True

  2. False


Correct Option: A
Explanation:

Magnetic force

All magnetic materials lose their magnetic properties when:

  1. Dipped in water

  2. Dipped in oil

  3. Brought near a piece of iron

  4. Strongly heated


Correct Option: D
Explanation:
Curie- Temperature:
The temperature at which any magnetic field material loses its magnetic property which is at a much higher temperature thus being strongly heated,
Magnets can be demagnetized.

Identify when the magnet looses their property?

  1. On hammering

  2. On beating

  3. On dropping it from certain height

  4. When used in electric circuits


Correct Option: A,B,C
Explanation:

The magnet can loose it property heating, by hammering and by using demagnetizing field we can demagnetize a magnet,On dropping it from certain height.

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Which all things can be used to make a magnet?

  1. Iron nail

  2. Needle

  3. Blade

  4. Wood


Correct Option: A,B,C
Explanation:

Materials that can be magnetized, which are also the ones that are strongly attracted to a magnet, are called ferromagnetic (or ferrimagnetic). These include iron, nickel, cobalt, some alloys of rare-earth metals, and some naturally occurring minerals such as lodestone.

A magnet can be easily turned into a ______ by excessive heating. Fill in the blank.

  1. Electromagnet

  2. Permanent Magnet

  3. Temporary Magnet

  4. All of the above


Correct Option: B
Explanation:

A magnet can be easily turned into a permanent magnet by excessive heating.

Rock of material which attract is termed as

  1. magnet

  2. magnetite

  3. magnesia

  4. magnetic


Correct Option: B

Which of the following process are used to make a magnet?

  1. Casting of magnetic material

  2. Pressing and sintering of magnetic material

  3. Extruding of magnetic material

  4. All of the above


Correct Option: D
Explanation:

Casting of a magnetic material, pressing and sintering of magnetic material and extruding of magnetic material are the processes used for making permanent magnets.