Making a Magnet

Q.

Differentiate between the geographic north pole and magnetic north pole.

Q.

What is a magnetic compass? State its use. [3 MARKS]

Q. what are magnet keepers

Q.

Classify the following into magnetic and non-magnetic materials. Give reasons. [3 MARKS]

Rubber, wood, steel, iron nails, cobalt, plastic

Q.

Suggest an activity to prepare a magnetic compass by using an iron needle and a bar magnet.

Q. A magnet is an object that attracts iron objects. This phenomenon is known as _________.

1. Electrostatic force
2. Magnetism
3. Hawking radiations
4. Nuclear physics

Q.

How can we safely keep bar magnet so that they don't lose their magnetic property?

Q.

Question 18

Boojho kept a magnet close to an ordinary iron bar. He observed that the iron bar attracts a pin as shown in the figure.

What inference could he draw from this observation? Explain.

Q. Which among the following is true?
(i) All metals are magnetic materials.
(ii) All non-metals are non-magnetic materials.

1. Only (i)
2. Only (ii)
3. Both (i) and (ii)
4. None of (i) and (ii)

Q.

Question 15

Describe the steps involved in magnetising an iron strip with the help of a magnet.

Q. Identify the best evidence of the Earth having a magnetic field.

1. All things fall towards the Earth's center
2. Wind blows from East to West
3. Oceans on Earth have current
4. All compass needles lines up with it

Q.

Sohan has a bar magnet and three rods, labelled A, B and C and each end of the rod X and Y. He brought the two poles of the bar magnet near each end X and Y of the rods. He recorded the results as follows :

Rod	Observations
A	X was attracted to the north pole of the magnet but Y was repelled.
B	Both X and Y were attracted to the south pole of the magnet.
C	When the magnet was brought near X or Y , it had no effect.

Fill in the blanks with a magnet/non-magnetic material/magnetic material.

1. Rod A - ______________
2. Rod B - _______________
3. Rod C - ________________

Q.

A substance which is feebly repelled by magnet is a ___________

1. diamagnetic substance

2. paramagnetic substance

3. ferromagnetic substance

4. none of the above

Q. What will happen to a plastic rod if a bar magnet is brought near it?

1. It will attract towards magnet.
2. It will repel away from magnet.
3. It will either attract or repel depending on polarity of magnet.
4. It will not move at all.

Q. What are magnetic keepers ?

Q.

How you will test whether a given substance is magnet or not?

Q.

We can use an electromagnet to lift very heavy iron loads

1. True
2. False

Q.

Which of the following is a method of magnetising a magnetic material?

1. Induction

2. Distillation

3. Evaporation

4. None of these

Q.

Question 8

You are given an iron strip. How will you make it into a magnet?

Q.

How is an electromagnet better than a permanent magnet ?

Q. Two circular coils mounted parallel to each other on the axis carry steady current. If an observer between the coil reports that one coil carry current in clockwise direction while other in counter clockwise direction then there is 1)steady repulsive force 2)zero force 3)a repulsive force 4)a steady attractive force

Q. Which among the following is true?
(i) All metals are magnetic materials.
(ii) All non-metals are non-magnetic materials.

1. Only (i)
2. Only (ii)
3. Both (i) and (ii)
4. None of (i) and (ii)

Q. Name the type of force which acts in the following case:​

• A magnet attracts an iron pin.​

Q. ntTwo circular coils mounted parallel to each other on the same axis carry steady currents. If an observer between the coils reports that one coil carrying a clockwise current I , while other is carrying a counter clockwise current I, between the two coils, then there is A steady repulsive force B zero force C a repulsive force D steady attractive forcen ntn

Q.

Which of the following is a natural magnet?

1. iron

2. magnetic needle

3. bar magnet

4. magnetite

Q.

A temporary magnet is made up of

1. steel

2. cast iron

3. soft iron

4. stainless steel

Q.

A compass has a small balanced pointer that always points North-South when suspended freely. This is because :

1. The Earth has a magnetic field and the pointer is magnetic.

2. The Earth doesn't have any magnetic field.

3. The compass needle points to cold places.

4. Of gravitational force of the Earth.

Q. Identify the location where a magnetic compass would work.

1. Only on high mountains
2. Only in oceans
3. Within Earth's magnetic field
4. In outer space

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

1. True
2. False

Q. The earth itself acts as a huge

1. disc magnet
2. horse shoe magnet
3. bar magnet