Magnetic Material

Q. Alnico is a alloy of

1. iron.
2. cobalt.
3. nickel.
4. aluminium.

Q. The materials which are attracted towards a magnet are called materials.

1. magnetic
2. conducting
3. metallic
4. non-magnetic

Q. Nipermag is a alloy made of

1. Nickel
2. Iron
3. Aluminium
4. Cobalt

Q. You are given a steel bar. How will you convert it into a temporary magnet?

1. By putting into hot water.
2. By placing another steel bar alongside it.
3. By rubbing it with a magnet for few minutes.
4. It can't be converted.

Q.

Which type of magnets are stronger, natural or artificial magnets?

Q. Which of the metal combinations is used for making the alloy Nipermag?

1. Iron, nickel, aluminium and titanium
2. Copper, iron, aluminium, cobalt
3. Iron, tin, copper, titanium
4. Copper, tin, nickel, zinc

Q. Which among the following statements is false regarding magnets?

1. They produce heat when placed in sunlight.
2. They attract certain materials such as iron and nickel.
3. When freely suspended, they align themselves in the direction of Earth's magnetic field.
4. They exert an attractive or repulsive force on other magnets.

Q.

A very powerful magnetic substance is prepared by mixing magnetite with:

1. calcium oxide

2. copper oxide

3. barium oxide

4. none of these

Q.

What grade stainless steel is magnetic ?

Q.

A current-carrying metallic comb is placed close to small iron fillings, then the

1. iron filings will fly away from the comb, when switch is turned off.

2. iron filings align in the direction of the magnetic field produced around the metallic comb

3. iron filings will be attracted by the comb

4. Both (b) and (c)

Q.

Examples of magnetic materials is/are

1. iron

2. nickel

3. cobalt

4. all of these

Q.

What are non-magnetic materials?

Q.

What are the uses of magnets? Think and answer.

Q. Vishnu brought a piece of magnet near 3 pins made up of different materials. Pins Y and Z get attracted whereas pin X remains in its place as shown below.

What are the pins 'X', 'Y', and 'Z' made up of?

1. Pix X - Aluminium
   Pin Y - Nickel
   Pin Z - Steel
2. Pix X - Cobalt
   Pin Y - Iron
   Pin Z - Steel
3. Pix X - Copper
   Pin Y - Iron
   Pin Z - Steel
4. Pix X - Copper
   Pin Y - Brass
   Pin Z - Cobalt

Q. When a permanent magnet is brought near a magnetic material for a short time, the material acquires ________.

1. induced magnetism
2. electromagnetism
3. permanent magnetism
4. stronger magnetism

Q.

A magnet always attracts wood.

1. True
2. False

Q.

Arrange the following steps in sequential order to magnetize a steel bar with a strong permanent magnet.

(A) Keep the steel bar to be magnetized on a wooden table.

(B) Take a strong permanent magnet and bring one pole (say north pole) of the magnet near one end of the steel bar and gently rub from one end.

(C) Once it has reached the other end, lift the magnet gently away from the steel bar and again bring it to the starting end.

(D) Repeat this process several times so that the steel bar is magnetized with the starting end as the north pole and the other end as the south pole.

1. A C B D

2. B A C D

3. A B C D

4. A D B C

Q.

Vishnu holds a magnet above 3 pins made of different materials. Pins Y and Z gets attracted whereas pin X remain in its place.

What metals can the pins X, Y and Z be made of?

Pin X Pin Y Pin Z

a. Copper Iron Steel

b. Steel Nickel Aluminium

c. Copper Brass Cobalt

d. Iron Copper Brass

KINDLY EXPLAIN

Q.

How will you test that 'tea dust' is not adulterated with iron powder?

1. Heat the mixture

2. Mix it in water

3. Put the mixture under fan

4. Place a bar magnet near the mixture

Q. Which among the following materials gets attracted by a magnet?

1. Paper boat
2. Wooden bat
3. Plastic comb
4. Iron nail

Q.

Which of the following is a magnetic substance?

1. Wood

2. Nickel

3. Chinaware

4. Glass

Q.

Which among the following material cannot be used to make a magnet?

1. Steel

2. Copper

3. Cobalt

4. Iron

Q.

Which of the following gets attracted by a magnet?

1. Steel

2. Wood

3. Plastic

4. Paper