Physics · Magnetism And Matter · NEET
No. This is the most common mistake. When you cut a bar magnet, each half instantly forms its own new north AND south pole. You end up with two smaller bar magnets, each complete with both poles. You can keep cutting into tiny pieces — every piece is still a full dipole. You never isolate a lone pole.
A magnetic monopole would be a single, isolated magnetic charge — just a north pole with no south, or just a south with no north — like how a proton (+) and an electron (-) exist separately as electric charges. No experiment has ever found one. The simplest magnetic object is always a dipole (a pole pair), so magnetism has no true 'sources' or 'sinks' the way electric charge does.
An isolated positive or negative electric charge exists (e.g. charge e = 1.6 x 10^-19 C). But magnetism does not come from magnetic 'charges' — it comes from moving charges and circulating currents inside atoms. A bar magnet acts like a bundle of tiny current loops. Cutting it just gives you more current loops, each still behaving as a dipole. Since the source is a loop, not a charge, you can't get a lone pole.
Yes. NCERT states that breaking a bar magnet into halves gives two similar bar magnets 'with somewhat weaker properties.' Each smaller magnet has a smaller magnetic dipole moment because it contains fewer aligned atomic current loops, but it is still a complete magnet.
Because there is no isolated pole, magnetic field lines never start or end at a point — they always form continuous closed loops (passing through the magnet). Electric field lines can start on a + charge and end on a - charge because those charges exist alone. Magnetic lines have nowhere to 'begin' or 'stop', which is exactly what 'no monopole' means.
Try the real previous-year questions from this chapter — each with the answer and a full solution.
No. No isolated single magnetic pole has ever been observed in nature. The simplest magnetic element is always a dipole (a north-south pole pair) or a current loop.
You get two smaller bar magnets, each with its own north and south pole and somewhat weaker magnetic properties. This is true whether you cut across the length or along it.
An electric dipole is built from two separate real charges (+q and -q) that can exist alone. A bar magnet's poles cannot be pulled apart because magnetism comes from circulating currents, not from isolated magnetic charges.
Because no isolated pole exists, the net magnetic flux through any closed surface is zero: the flux integral of B over a closed surface = 0. Field lines that enter a surface must also leave it. In electrostatics the same integral equals the enclosed charge over epsilon-0, because isolated charges do exist.
A bar magnet behaves like a large number of tiny circulating atomic current loops (like cutting a solenoid gives two smaller solenoids). Each loop is a dipole, so no cut can ever produce a single pole.
