Magnetic Needle

Q. The first compass was invented using the .

1. iron
2. copper
3. lodestone
4. electromagnet

Q.

What is the practical application of magnet ?

Q. Magnetic compass needle is made up of ______.

1. plastic
2. steel
3. wood
4. paper

Q. Who invented magnet?

Q.

Is the magnetic dipole moment a vector or a scalar?

Q.

Question 17

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

Q.

Which of the following device is used for navigation?

1. Speedometer

2. Compass

3. Barometer

4. Thermometer

Q.

Name the following:

A natural magnet.

Q.

Initially, sailors used to find direction by suspending a piece of ____.

1. Electromagnet

2. Magnetic compass

3. None of these

4. Bar magnet

Q. Which device was used by pilots and navigators to find the direction in earlier times?

1. Sundial
2. Barometer
3. Magnetic compass
4. Thermometer

Q. Which of the following material was once used as a magnetic compass in ancient times?

1. Lodestone
2. Bronze
3. Brass
4. Soft iron

Q. Identify the following device: Which of the following objects can it detect?

• Belt
• Mobile phone
• Handkerchief
• Coins

Q. Which of the following statements are true about the needle in a magnetic compass?

1. It can attract magnetic materials.
2. When a magnet is brought near, it gets deflected.
3. It aligns with the Earth's magnetic field even when another magnet is brought near it.
4. When freely suspended, it comes to rest in the Earth's north-south direction.

Q.

what is the material used in the pointer of magnetic compass and why only it is used ?

Q. A magnetic compass is used to indicate

1. directions
2. speed
3. distance
4. time

Q.

Which of the following(s) can be used for navigation?

1. Magnetic compass

2. Plastic wire

3. Wooden block

4. Bar magnet

Q.

Give two examples of the following:
(i) magnetic materials
(ii) non -magnetic materials
(iii) Devices that use magnetic materials

Q.

Matt has a magnetic compass which is pointing in the north-south direction. He brings a large magnet close to it. In which direction would the magnetic needle align?

1. It would align in the east-west direction.

2. It would align in the south-north direction .

3. It would remain unchanged.

4. It would align itself according to the resulting magnetic field of the Earth and the larger magnet.

Q. We should pivot the compass needle on a sharp pin to _______.

1. To minimise the magnetic effect on the pin
2. To maximise the friction between the pin and the compass needle
3. To minimise the friction between the pin and the compass needle
4. To ensure that the compass needle will not drop from the pivoted point.

Q.

A compass has a small balanced pointer that points towards the North-South direction. This is because:

1. Gravity deflects the needle point towards North-South.

2. The compass needle points to random direction.

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

4. The motion of compass is influenced by other celestial bodies.

Q.

Name the device used by sailors to find directions.

1. Protractor

2. Needle

3. Magnetic compass

4. Sextant