Concept:The Earth possesses a relatively weak intrinsic magnetic field that protects the atmosphere from solar wind.
Formula:$$ \text{Earth's field range: } 25 \ \mu\text{T} \text{ to } 65 \ \mu\text{T} $$
Solution:- Expressed in Tesla, the Earth's field is about \( 0.25 \times 10^{-4} \ \text{T} \) to \( 0.65 \times 10^{-4} \ \text{T} \).
- The unit Gauss (G) is related to Tesla by \( 1 \ \text{T} = 10^4 \ \text{G} \).
- Converting the range to Gauss gives: \( 0.25 \ \text{G} \) to \( 0.65 \ \text{G} \).
- Option A (\( 0.6 \ \text{G} \)) falls perfectly within this standard physical range.
Why other options are incorrect:Options B, C, and D are extremely massive magnetic fields (MRI machines operate around 1.5 to 3 Tesla). Life on Earth would be vastly different if the field was on the order of full Teslas.
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