# How many neutral points on a horizontal board are there when a manget is held vertically on the board

SAGAR SINGH - IIT DELHI
878 Points
13 years ago

Dear deepak,

If earth's magnetic field is considered as "B" ,then it has two components along horizontal and vertical.But while determining null or neutral points of a bar magnet only horizontal component of magnetic field is taken into consideration but not vertical component of magnetic field.

The reason Earth's magnetic field has a horizontal and vertical component is because it is oriented at angle with regard to the bar magnet in most places on Earth. Generally, you choose the reference frame to be that of the plane of the lab bar magnet. Of course you can also do it the other way and say that the lab bar magnet has a horizontal and vertical component while Earth magnet is purely in one direction but that makes things more complicated.

In the UK, the field lines lie about 70 degrees with regard to the horizontal. So when you conduct an experiment to measure the Earth's magnetic field by finding the null points between bar magnet and Earth magnet, you are only finding the horizontal component of the Earth's magnetic field.

All the best.

Sagar Singh

B.Tech IIT Delhi

sagarsingh24.iitd@gmail.com

OCEAN GODRE
40 Points
13 years ago

2

smriti
19 Points
7 years ago
One only because earth`s magnetic field is from S to N. The magnetic field of pole on the board is radial. Therefore there can be only one point on the board where magnetic field due to the pole cancels horizontal component of earth`s magnetic field
Ayush
36 Points
7 years ago

Dear deepak,

If earth's magnetic field is considered as "B" ,then it has two components along horizontal and vertical.But while determining null or neutral points of a bar magnet only horizontal component of magnetic field is taken into consideration but not vertical component of magnetic field.

The reason Earth's magnetic field has a horizontal and vertical component is because it is oriented at angle with regard to the bar magnet in most places on Earth. Generally, you choose the reference frame to be that of the plane of the lab bar magnet. Of course you can also do it the other way and say that the lab bar magnet has a horizontal and vertical component while Earth magnet is purely in one direction but that makes things more complicated.

In the UK, the field lines lie about 70 degrees with regard to the horizontal. So when you conduct an experiment to measure the Earth's magnetic field by finding the null points between bar magnet and Earth magnet, you are only finding the horizontal component of the Earth's magnetic field.

Antony Kiran K David
26 Points
6 years ago
2 as the earth has its magnetic field component in vertical direction,
the vertical component produced by the magnet is cancelled on either side of the magnet
ie. on the magnet’s equtorial points
Tarik
16 Points
5 years ago
The magnetic field is zero on equator because at equator angle of dip is zero and now if you take the magnet at equator then you will notice that their is no deflection in compass as earlier told that the angle of dip is zero.So only horizontal component is there and no dip is there.
Tarik
16 Points
5 years ago
If not told that the magnet is placed in north south or south north direction with the magnetic field of earth. Then assume once north south and then south north then your answer will be 4