Two identical coils carrying equal current have a common centre, and t...
Solution:
Given:
Two identical coils carrying equal current have a common centre, and their planes are at right angles to each other.
To find:
The ratio of the magnitude of the resultant magnetic field at centre and the field due to one coil alone.
Explanation:
When two identical coils carrying equal current have a common centre, and their planes are at right angles to each other, the magnetic field at the centre of the coils can be found as follows:
1. Magnetic field due to one coil:The magnetic field at the centre of one coil can be found using the formula:
B = (μ₀/4π) × (2I/R)
Where,
B = Magnetic field at the centre of the coil
μ₀ = Permeability of free space = 4π × 10⁻⁷ T m/A
I = Current flowing through the coil
R = Radius of the coil
2. Magnetic field due to one coil:The magnetic field at the centre of the two coils can be found using the formula:
B' = (μ₀/4π) × (4I/R)
Where,
B' = Magnetic field at the centre of the two coils
μ₀ = Permeability of free space = 4π × 10⁻⁷ T m/A
I = Current flowing through each coil
R = Radius of each coil
3. Resultant magnetic field:The resultant magnetic field at the centre of the two coils can be found using the Pythagorean theorem:
B_res = √(B² + B'²)
4. Ratio of the magnitude of the resultant magnetic field and the field due to one coil alone:The ratio of the magnitude of the resultant magnetic field at centre and the field due to one coil alone can be found using the formula:
Ratio = B_res / B
Answer:
The ratio of the magnitude of the resultant magnetic field at centre and the field due to one coil alone is √2 : 1.