Question

By the 15th century, people on ships and boats solved the problem of finding out what direction they were

sailing in and, perhaps even more importantly, what direction they needed to go to get back home. Before

that time, sailors rarely ventured out of sight of land and instead relied on visible landmarks to get from

place to place. This limited traders and navies to routes close to shore, but the invention of the compass

changed all that.

The magnetic compass contains a magnetic element that aligns itself with the earth’s magnetic field.

Think of the earth as a big magnet. It has two magnetic poles, oriented north and south that are very close

to the geographic North and South Poles. When a magnet or a magnetic element (such as the mineral

lodestone or a ferrous metal that has been magnetized) is allowed to float freely, it will effectively point

north and south, thus showing you which direction you are going in relation to that axis.

Question 21

The compass always point towards the north. Which one of the following is the correct explanation for

this?

a) The Earth is a magnet and therefore it attracts the metallic needle of the compass.

b) The magnetic needle of the compass aligns itself with the Earth’s magnetic field.

c) The Earth’s south pole does not have a magnetic pull hence the compass points towards the

north.

d) The needle of the compass always points in the upward direction.

Question 22

From the image above what can you say about the direction of the magnetic field of the earth. The answer

has been started for you; complete it in terms of geographical north and south poles.

The magnetic lines of force of the earth emerge ……………………………………….............​

Answer 1

Answer:

answer 21-(a) is correct

answer 22-Earth is core and the geodynamo.the earth magnetic field is believed to be generated by electric currents in the conductive iron alloys of core, created by convection current due to heat escaping from the core