Engineering Physics

Solved Problems

1.     The magnetic susceptibility of silicon is −0.4 × 10⁻⁵. Calculate the flux density and magnetic moment per unit volume when magnetic field of intensity 5 × 10⁵ A/m is applied.

sol: Given: χ = –0.4 × 10^‒5

H = 5 × 10⁵ A /m

B = ? and M = ?

B = μ₀(H + M) = μ₀ H(1 + χ)

    = 4π × 10^‒7 × 5 × 10⁵ [1 – 0.4 × 10^‒5] = 4π × 5 × 10^‒2 × 0.9996 = 0.62 Wb/m²

M = χH = –0.4 × 10^–5 × 5 × 10⁵ = –2.0 A/m.

2.     The magnetic field strength in silicon is 1000 A/m. If the magnetic susceptibility is −0.25 × 10⁻⁵, calculate the magnetization and flux density in silicon.

sol: Magnetic field strength (H) = 1000 A/m

Magnetic susceptibility (χ) = –0.25 × 10^‒5

Magnetization (M) = χH = –0.25 × 10^‒5 × 1000 = –0.25 × 10^‒2 A/m.

Magnetic flux density ( ...