Magnetism And Matter

The magnetic flux (Φ) through a material is:
Φ = B * A
Given:
Magnetizing field (B) = 1000 A/m
Magnetic flux (Φ) = 2.4 x 10^-5 Wb
Cross-sectional area (A) = 0.3 cm²
First, we need to convert the cross-sectional area from cm² to m²:
A = 0.3 cm² = 0.3 x 10^-4 m²
Rearranging the equation
Φ = B * A,
we can solve for B:
B =
Substituting the given values:
B =
B =
B = 0.8 Wb/m²
μ =
μ =
μ = 8 x 10^-4 (Wb/A)
The magnetic permeability in SI units is henries per meter (H/m). Since 1 Wb/A = 1 H, we have:
μ = 8 x 10^-4 H/m
Therefore, the correct answer is (B) 8 x 10^-4.

Ferromagnetism refers to the property of certain materials to form permanent magnets or be attracted to magnets. Among the given options:

• Zinc (Zn): It is a diamagnetic material and does not exhibit ferromagnetic properties.
• Copper (Cu): Copper is also diamagnetic, showing no ferromagnetic behavior.
• Manganese (Mn): Manganese is paramagnetic in its pure state but not ferromagnetic.
• Chromium (Cr): Chromium is typically antiferromagnetic at room temperature, but certain alloys can exhibit ferromagnetic behavior.

The correct answer as ferromagnetic is Chromium, particularly in specific alloyed forms.

We are given the following data:

• Length of the solenoid
• Number of turns
• Current

Step 1: Recall the formula for the magnetic field inside a solenoid

The magnetic field inside a solenoid is given by the formula:

Step 2: Substitute the values into the formula

Step 3: Simplify the calculation

Conclusion:

The magnetic field at the center of the solenoid is .