A long solenoid with 1000 turns/m has a core material with relative permeability 500 and volume 10³ cm³. If the core material is replaced by another material having relative permeability of 750 with same volume maintaining same current of 0.75A in the solenoid, the fractional change in the magnetic moment of the core would be approximately $\left(\frac{x}{499}\right).$  Find the value of x.

There are various important topics in the physics chapter 5 class 12 magnetism and matter. These topics are important for both cases, conceptual and numerical questions. Read below:

• Magnetism 
• Bar Magnet as an Electromagnet
• Magnetic Field Due to Magnetic Dipoles
• Type of Magnetic Materials: Ferromag

In JEE Main exam, it is a significant chapter. There can be 6 to 8 questions from this chapter, a weightage of nearly 6.6%.

The exact weightage varies from year to year. This chapter comes under a broader category which can be "Magnetism" or "Modern Physics". In NEET exam, the chapter's weightage is low to moderate and there can be 6-7% of questions from this chapter.

The chapter is one of the small and easy chapter of class 12 Physics. It includes - properties of magnetic materials, magnetic dipoles, and Earth's magnetic field.

When the electric charges moves, it creates attraction or repulsion. It creates magnetic forces and fields and called magnetism. The term "magnetism and matter" talks about the way magnetic forces and matter interact.