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Exploring Magnets - Poles of Magnet

Grade 6CBSE

Review the key concepts, formulae, and examples before starting your quiz.

🔑Concepts

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Magnetic poles are the regions at the ends of a magnet where the magnetic force is the strongest. Every magnet has two poles: the North Pole (NN) and the South Pole (SS).

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The magnetic strength is maximum at the poles and decreases as we move toward the center of the magnet. At the exact center, the magnetic force is effectively zero.

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Directive Property: When a bar magnet is suspended freely by a thread, it always comes to rest in the North-South direction. The end pointing towards the Earth's geographic North is the NN pole, and the end pointing towards the geographic South is the SS pole.

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Interaction between poles: Like poles (same) repel each other, whereas unlike poles (opposite) attract each other. For example, N−NN-N or S−SS-S will push away, while N−SN-S will pull together.

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Magnetic poles always exist in pairs. If a magnet is broken into two halves, each piece will automatically develop its own NN and SS poles. Magnetic monopoles (a single pole) cannot exist.

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The Earth itself behaves like a giant bar magnet with its magnetic poles located near the geographic poles.

📐Formulae

Like Poles→Repulsion\text{Like Poles} \rightarrow \text{Repulsion}

Unlike Poles→Attraction\text{Unlike Poles} \rightarrow \text{Attraction}

Number of Poles=2×Number of Magnet Pieces\text{Number of Poles} = 2 \times \text{Number of Magnet Pieces}

💡Examples

Problem 1:

A student has a bar magnet that is not labeled. How can they identify the North Pole using only a piece of thread?

Solution:

By suspending the magnet freely using the thread.

Explanation:

Due to the directive property of magnets, a freely suspended magnet will align itself with the Earth's magnetic field. The end of the magnet that points towards the geographic North direction is the NN pole of the magnet.

Problem 2:

If a bar magnet is cut into 33 equal pieces, how many North poles and how many South poles will be there in total?

Solution:

33 North poles and 33 South poles.

Explanation:

Since poles always exist in pairs, each of the 33 pieces will become an independent magnet. Total poles = 3×2=63 \times 2 = 6. Specifically, each piece has one NN and one SS, resulting in 33 of each.

Problem 3:

Two magnets are placed near each other. Magnet AA has its SS pole facing Magnet BB. If they attract each other, which pole of Magnet BB is facing Magnet AA?

Solution:

The North Pole (NN).

Explanation:

According to the Law of Magnetism, attraction occurs between unlike poles. Since Magnet AA presents a South pole (SS), Magnet BB must present a North pole (NN) for attraction to occur.