The correct answer is (C) 4B. Magnetic induction at the center of a circular coil with n turns is given by B′ = n² B. For two turns (n = 2), the magnetic induction becomes B′ = 2²B = 4B, ...
Category: Class 12 Physics
NCERT Solutions for Class 12 Physics updated for CBSE academic session 2021-2022.
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The correct answer is (B) B/4. The magnetic field due to a long straight current-carrying wire is given by B ∝ 1/r. If the distance is increased from 5 cm to 20 cm (4 times), the magnetic field decreases by ...
The correct answer is (C) 4B. Magnetic induction at the center of a circular coil with n turns is given by B′ = n² B. For two turns (n=2), the magnetic induction becomes B′ = 2²B = 4B, quadrupling the ...
The correct answer is (C) Torsional constant k. Sensitivity of a galvanometer is given by S = nBA/K. Decreasing the torsional constant k increases sensitivity as it reduces the restoring torque per unit twist, allowing greater deflection for a given ...
Let the length of each wire be L. For the square, side = L/4; area = (L/4)² = L²/16. For the circle, radius = L/2π; area = π(L/2π)² = L² /4π. Ratio of magnetic moments = L²/4π/L²/16 = 16/4π = ...