What should be the value of the self-inductance of an inductor that should be connected to a 220 V, 50 Hz supply so that a maximum current of 0.9 A flows through it?

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Accepted Answer

(3) 1.1 H. Given: Vᵣₘₛ = 220 V, f = 50 Hz, maximum (peak) current I₀ = 0.9 A. Idea: the supply's 220 V is an rms value, so the peak voltage is V₀ = √2×220 ≈ 311 V, and the peak current is I₀ = (V₀)/(X_L). X_L = (V₀)/(I₀) = (311.1)/(0.9) ≈ 345.7 Ω. L = (X_L)/(2π f) = (345.7)/(2π×50) = (345.7)/(314.2) ≈ 1.1 H. (Using 220 V with 0.9 A would give 0.78 H, which is not offered: the question means the peak current.)

What should be the value of the self-inductance of an inductor that should be connected to a 220 V, 50 Hz supply so that a maximum current of 0.9 A flows through it?

Step-by-step solution

Why the other options are wrong