JEE Main 2026 Physics question
Not in JEE Advanced syllabus
A solenoid has a core made of material with relative permeability 400. The magnetic field produced in the interior of solenoid is 1.0 T. The magnetic intensity in SI units is α × 10⁵. The value of α is . (Free space permeability μ₀ = 4π × 10⁻⁷ SI units.)
Answer: (B)
Solution
H = B/(μ₀μᵣ) = 1/(4π×10⁻⁷×400) = 10⁷/(1600π) = (1/16π)×10⁵.