Magnetism is a force that magnets and electric currents produce. Magnetic field intensity tells us how strong a magnetic field is at a certain spot.

Understanding magnetic fields and their intensity is crucial in various fields like physics, engineering, and even in everyday devices like smartphones and computers. In this article, we will explore what magnetic field intensity is, how it is calculated, and why it is important.

What is a Magnetic Field?

Magnetic field is like a bubble around a magnet with electric flow. It is invisible but can pull or push magnets or magnetic stuff nearby. It is an invisible region around a magnet or a conductor carrying an electric current where magnetic forces are exerted.

It is like an invisible force that guides magnets and affects magnetic materials within its range.

What is Magnetic Field Intensity?

Magnetic field intensity tells us how strong a magnetic field is at a certain spot. It is like a measure of the magnet’s powers. We measure it using units called tesla or gauss.

Magnetic field intensity is a measure of the strength of a magnetic field at a specific point in space. In simpler terms, it tells us how strong the magnetic force is at a particular location. Magnetic field intensity helps us describe the difference in strength at various points around the magnet.

How to Calculate Magnetic Field Intensity at Different Points

There are different ways to calculated magnetic field intensity. For a current carrying wire the formula used to calculate the magnetic field intensity is given below:

Axial Point

Imagine a point along the line of a wire. To find the magnetic field intensity there, we use a simple formula:

[Tex]\Beta = \frac{\mu_0 . I}{2.\pi.r}[/Tex]

Here,

B is the magnetic field intensity,

????₀ is constant,

I is the electric current, and

r is the distance from the wire.

Equatorial Point

For a point at the same height as a wire loop. Here’s how we figure out the magnetic field intensity:

[Tex]\Beta = \frac{\mu_0 . I.R^2}{2.(R^2 + x^2)^\frac{3}{2}}[/Tex]

In this formula,

B is the magnetic field intensity,

????₀ is constant,

I is the electric current,

R is the loop’s radius, and

x is the distance from the center of the loop.

Sample Problems on Magnetic Field Intensity

Problem 1: A straight wire carries a current of 2.5 A. Calculate the magnetic field intensity at a distance of 0.1 meters from the wire.

Solution:

Given: Current (I) = 2.5 A, Distance from wire (r) = 0.1 m

Using the formula for magnetic field intensity near a straight wire:

[Tex]\Beta = \frac{\mu_0 . I}{2.\pi.r}[/Tex]

Where, ????₀ is the permeability of free space (constant).

Substituting the given values:

[Tex]\Beta = \frac{4\pi \times 10^{-7} \times 2.5}{2\times\pi\times0.1}[/Tex]

[Tex]\Beta = \frac{2.5 \times 10^{-6}}{0.2}[/Tex]

B = 1.25 × 10^-5 T

So, the magnetic field intensity at a distance of 0.1 meters from the wire is B = 1.25 × 10^-5 T

Problem 2: A circular wire loop with a radius of 0.05 meters carries a current of 3 A. Calculate the magnetic field intensity at the center of the loop.

Solution:

Given: Current (I) = 3 A, Radius of loop (R) = 0.05 m

Using the formula for magnetic field intensity at the center of a circular loop:

[Tex]\Beta = \frac{\mu_0 . I.R^2}{2.R^2}[/Tex]

[Tex]\Beta = \frac{4\pi \times 10^{-7} \times 3 \times (0.05)^2}{2\times(0.05)^2}[/Tex]

[Tex]\Beta = \frac{3\pi \times 10^{-7} \times 3 \times (0.0025)}{0.05}[/Tex]

[Tex]\Beta = \frac{7.5 \times 10^{-10}}{0.05}[/Tex]

B = 1.5 × 10^-8 T

So, the magnetic field intensity at the center of the loop is B = 1.5 × 10^-8 T

Problem 3: A solenoid with 200 turns per meter carries a current of 5 A. Calculate the magnetic field intensity inside the solenoid.

Solution:

Given: Current (I) = 5 A, Number of turns per meter (N) = 200

Using the formula for magnetic field intensity inside a solenoid:

B = ????₀ . N . I

Substituting the given values:

B = 4???? × 10^-7 . 200 . 5

B = 4???? × 10^-7 . 1000

B = 4???? × 10^-4 T

So, the magnetic field intensity inside the solenoid is B = 4???? × 10^-4 T

Read More,

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• How to Calculate Force of Gravity
• How to Calculate the Change in Momentum of an Object?

Practice Questions on Magnetic Field Intensity

Question 1: A wire carrying a current of 3 A is bent into a circular loop with a radius of 0.1 meters. Calculate the magnetic field intensity at the center of the loop.

Question 2: A solenoid has 500 turns per meter and carries a current of 4 A. Calculate the magnetic field intensity inside the solenoid.

Question 3: A straight wire carries a current of 5 A. Calculate the magnetic field intensity at a distance of 0.08 meters from the wire.

Question 4: A rectangular loop of wire carries a current of 2 A. The dimensions of the loop are 0.3 m by 0.4 m. Calculate the magnetic field intensity at the center of the loop.

Question 5: A wire carrying a current of 8 A is bent into a semi-circle with a radius of 0.2 meters. Calculate the magnetic field intensity at the center of the semi-circle.

FAQs on Magnetic Field Intensity

What is a magnetic field?

The region around a magnet, moving charge or electromagnet in which other charges experience the magnetic forces is called the Magnetic Field.

Why is magnetic field intensity important?

It helps us understand how magnets work and design cool stuff like electric motors.

What is SI Unit of magnetic field intensity?

The SI unit of magnetic field intensity is Tesla.

What is magnetic field intensity also known as?

The magnetic field intensity is also known as strength of magnetic field or simply magnetic intensity.