Question

Difficulty: MediumMagnetism and Earth's Magnetic Field

At a magnetic observation station, the horizontal component of the Earth's magnetic field is 40 μT40\text{ }\mu\text{T} and the vertical component is 30 μT30\text{ }\mu\text{T}. What is the total magnetic field intensity of the Earth at this station in μT\mu\text{T}?

Answer: 50 μT

Answer

The total magnetic field intensity of the Earth at this station is 50 μT50\text{ }\mu\text{T}.
The horizontal component (BhB_h) and vertical component (BvB_v) of the Earth's magnetic field act at right angles to each other. Therefore, the resultant total magnetic field intensity (BB) is calculated using vector addition: B=Bh2+Bv2=402+302=50 μTB = \sqrt{B_h^2 + B_v^2} = \sqrt{40^2 + 30^2} = 50\text{ }\mu\text{T}.

Step-by-Step Solution

1
Identify the vector relationship between the horizontal and vertical components of the Earth's magnetic field.
B=Bh2+Bv2B = \sqrt{B_h^2 + B_v^2}, where Bh=40 μTB_h = 40\text{ }\mu\text{T} and Bv=30 μTB_v = 30\text{ }\mu\text{T}.
The horizontal and vertical components of the Earth's magnetic field are mutually perpendicular vector components.
2
Substitute the values into the formula and solve for total magnetic field intensity BB.
B=(40)2+(30)2=1600+900=2500=50 μTB = \sqrt{(40)^2 + (30)^2} = \sqrt{1600 + 900} = \sqrt{2500} = 50\text{ }\mu\text{T}.
Applying the Pythagorean theorem yields the magnitude of the resultant magnetic field vector.

Key Concept

Resolution of Earth's magnetic field into horizontal (BhB_h) and vertical (BvB_v) components.
Estimated Time:1m 0s
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