The primary current for the 120-V/24-V transformer rated at 20 VA is approximately 0.17 A.

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Multiple Choice

The primary current for the 120-V/24-V transformer rated at 20 VA is approximately 0.17 A.

A transformer’s VA rating tells how much apparent power it can handle. With a 20 VA rating and a primary voltage of 120 V, the primary current is I_p ≈ 20 VA / 120 V = 0.1667 A, about 0.17 A. This aligns with the statement. You can check consistency on the secondary side: I_s ≈ 20 VA / 24 V ≈ 0.833 A. In an ideal transformer, currents relate as I_p / I_s = V_s / V_p, so I_p ≈ I_s × (V_s / V_p) ≈ 0.833 × (24/120) ≈ 0.167 A, confirming the primary current of about 0.17 A.

A transformer’s VA rating tells how much apparent power it can handle. With a 20 VA rating and a primary voltage of 120 V, the primary current is I_p ≈ 20 VA / 120 V = 0.1667 A, about 0.17 A. This aligns with the statement.

You can check consistency on the secondary side: I_s ≈ 20 VA / 24 V ≈ 0.833 A. In an ideal transformer, currents relate as I_p / I_s = V_s / V_p, so I_p ≈ I_s × (V_s / V_p) ≈ 0.833 × (24/120) ≈ 0.167 A, confirming the primary current of about 0.17 A.

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