Solved UPSC CDS/OTA Question
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Q · MagnetismModerate · 45s
In a tangent galvanometer, the deflection is 45° when current is 0.1 A. If radius is 10 cm, number of turns is 20, find horizontal component of Earth's magnetic field (μ₀=4π×10⁻⁷ T·m/A): 277
TopicMagnetism
Question Typemultiple choice
DifficultyModerate
Marking+1 / −0.33
Test Duration30 min
Step-by-Step Solution
The complete worked solution.
Every step explained — no skipped algebra.
Bh = μ₀nI/(2R) × tan₄₅° = (4π×10⁻⁷×20×0.1)/(2×0.1) = 2.52×10⁻⁵ T.
285
Final Answer: Option B — 2.52×10⁻⁵ T
281