listen friends.......... please dont leave this unanswered or the confusion is sure to kill me....

Considering Pradeep's Fundamental Physics , IIT Physics (JPNP) old edition and of course the superhit HCV as good books....... please try to understand my problem...

In Pradeep's 2nd year book (old edition - the big sized one)...go to page 3/113. For new book users ... i m talking about the chapter - ' Magnets and Earth's Magnetism ' . In the mentioned page (not same for new books) , you will find there a definition of magnetic field stength (B) under the art. 3(c).4. as the force experienced by a hypothetical unit north pole placed in a magnetic field

At the end of this article they have also warned us of the fact that other books might be using the word magnetic induction instead magnetic field strength.

Now go to IIT Physics 2nd year (old edition) ..page 479 -

chapter 7 - ' Magnetism ' . In that page, under art. 7.22 the 1st defition of magnetic intensity or magnetising force (H) is given as the force experienced by a hypothetical unit north pole placed in a magnetic field. But in the next page, when they went on to discuss Magnetic induction, they didnot mention a word about what Pradeep's had told us . Instead they have written the definition of Pradeep's magnetic induction or field strength (B) under magnetising force (H).

Now lastly to the common-to-all HCV - 2 page 255 - chapter - ' Permanent Magnets ' . There you will find under art. 36.1 , an equation also numbered as 36.1 which says (vector)F = m.(vector)B. This equation is in accordance with the definition magnetic induction or field strength (B) as stated in Pradeep's that it is the force experienced by unit north .... (and so on).

Although i did not find in HCV , a contradicting statement.... but still this equation contradicts IIT Physics's definition of H.

Please friends .....help me solve this puzzle.... what is the actual definition of B and H..... who is correct PFP , IITP or HCV

It sounds like you're grappling with some nuanced definitions in magnetism, particularly regarding the terms magnetic field strength (B), magnetic intensity (H), and magnetic induction. These concepts can indeed be confusing, especially when different textbooks present them in varying ways. Let’s break this down to clarify the definitions and relationships between these terms.

Understanding Magnetic Field Strength (B) and Magnetic Intensity (H)

In the realm of magnetism, the terms magnetic field strength (B) and magnetic intensity (H) are often used, and their definitions can vary slightly depending on the context or the textbook. Here’s how they are generally understood:

Magnetic Field Strength (B)

Magnetic field strength, often denoted as B, is defined as the magnetic force experienced by a hypothetical unit north pole placed in a magnetic field. This definition is consistent across various sources, including Pradeep's Fundamental Physics. The unit of B is the Tesla (T), and it represents the strength and direction of the magnetic field at a given point.

Magnetic Intensity (H)

Magnetic intensity, represented as H, is defined as the magnetizing force produced by an electric current or a magnet. It is also described as the force experienced by a hypothetical unit north pole in a magnetic field, but it is measured in a different context. The unit of H is the Ampere-Turn per meter (A/m). In many cases, H is used to describe the magnetic field in materials, particularly in the context of magnetization.

Clarifying the Differences

To clarify the apparent contradictions between the textbooks:

• Pradeep's Definition: It defines B as the force on a unit north pole, which aligns with the general understanding of magnetic field strength.
• IIT Physics Definition: It describes H similarly, but when discussing magnetic induction, it may not explicitly differentiate between B and H, leading to confusion.
• HCV's Equation: The equation F = m.B indicates that the force on a magnetic pole is proportional to the magnetic induction B, which is consistent with Pradeep's definition.

Interpreting the Relationships

In many contexts, especially in free space, the relationship between B and H can be expressed as:

B = μH

Where μ is the permeability of the medium. This equation shows that B and H are related but not identical; B accounts for the material's response to the magnetic field, while H represents the applied magnetizing force.

Conclusion: Who is Correct?

All three sources—Pradeep's, IIT Physics, and HCV—are correct in their contexts. The confusion arises from the different ways they frame the definitions and the relationships between B and H. It's essential to understand that while B and H can be defined similarly in terms of the force on a unit north pole, they serve different purposes in magnetism. When studying these concepts, focus on the context in which each term is used, and remember the fundamental relationship between them.

In summary, the definitions of B and H are not contradictory but rather complementary, each providing a different perspective on the behavior of magnetic fields. If you keep these distinctions in mind, it should help clear up the confusion you’re experiencing.