Coil center magnetic field B = μ₀NI/(2R). If N doubled, B becomes: MCQ with Answer and Explanation

Explanation:
Resistance R = V²/P = 220²/100 = 484 Ω. At 110 V, P = V²/R = 110²/484 = 12100/484 = 25 W. Assuming resistance constant. Power reduces to quarter when voltage halved (P ∝ V² for fixed R).

Explanation:
T = 1/(2×10⁶) = 0.5×10⁻⁶ s = 0.5 μs.

Explanation:
Moderator slows fast neutrons to thermal energies to increase probability of fission. Common moderators: heavy water, graphite. Control rods (cadmium, boron) absorb neutrons. Coolant removes heat.