Out of the given units which unit is for magnetic field intensity, H?

Explanation:

Magnetic Field Intensity (H):

Definition: Magnetic field intensity, denoted as H, is a vector quantity that represents the magnetizing force or the strength of a magnetic field. It measures how intensely a magnetic field is generated by a current-carrying conductor or by magnetic materials. The unit of magnetic field intensity is ampere-turns per meter (AT/m), which indicates the amount of current and the number of turns in a coil per unit length of the magnetic field.

Formula: Magnetic field intensity is mathematically expressed as:

H = (N × I) / L

• H: Magnetic field intensity (AT/m)
• N: Number of turns in the coil
• I: Current in the coil (amperes)
• L: Length of the magnetic path (meters)

Explanation of the Correct Option:

The correct unit for magnetic field intensity H is AT/m, i.e., ampere-turns per meter. This unit is derived from the relationship between the current flowing through a coil, the number of turns in the coil, and the length of the magnetic path.

When a current passes through a coil, it creates a magnetic field around the coil. The magnetic field intensity is directly proportional to the product of the current and the number of turns in the coil and inversely proportional to the length of the magnetic path. This relationship is fundamental to electromagnetism and is used in the design of magnetic circuits in various applications like transformers, motors, and generators.

Applications:

• Magnetic field intensity is a critical parameter in the design of electromagnetic devices like solenoids, inductors, and electromagnets.
• It helps in determining the strength of the magnetic field required for specific applications.
• Used in the analysis of magnetic circuits to evaluate the magnetizing force needed for magnetic materials to reach saturation.

Important Information

To further understand the other options, let’s evaluate them:

Option 2: ATm

This option is incorrect because ATm, or ampere-turns multiplied by meter, does not represent the unit of magnetic field intensity. Instead, it could represent a parameter related to the total magnetomotive force (MMF) when multiplied by the length of the magnetic path. Magnetic field intensity is a ratio and specifically involves the division of ampere-turns by meter, not multiplication.

Option 3: Am

This option is incorrect as well. Am, or ampere-meter, does not represent the unit of magnetic field intensity. This unit might be used to describe certain other electromagnetic properties, but it is not relevant in the context of magnetic field intensity. Magnetic field intensity requires the inclusion of the number of turns in the coil, making AT/m the correct unit.

Option 4: AT/m²

This option is also incorrect. AT/m², or ampere-turns per square meter, might suggest a quantity related to the density of magnetizing force over an area, but this is not the standard unit used for magnetic field intensity. Magnetic field intensity is measured in terms of ampere-turns per meter (AT/m), which is a linear measurement.

Conclusion:

Magnetic field intensity is a fundamental concept in electromagnetism, essential for understanding and analyzing magnetic circuits. The correct unit for magnetic field intensity is AT/m (ampere-turns per meter). By evaluating the other options, we confirm that none of them accurately represents the unit for magnetic field intensity, which is critical in designing and analyzing electromagnetic systems.