Two separate secondary windings rated at 120/240 V on a transformer have a total rating of 10 kVA. Each winding is rated at ___ kVA.

Two separate secondary windings rated at 120/240 V on a transformer have a total rating of 10 kVA. Each winding is rated at ___ kVA.

• A. 5
• B. 10
• C. 20
• D. 2

Answer: (A)

The amount of power a transformer secondary can deliver is shared among its windings. When two secondary windings are available, the total secondary kVA is the sum of the kVA ratings of each winding. If the total is 10 kVA and the windings are identical, each one must be able to carry half of that. So each winding is rated at 5 kVA. For context, at 120 V each winding rated at 5 kVA supports about 41.7 A. If connected in parallel for 120 V, the combined capability is about 83.4 A (10 kVA total). If connected in series for 240 V, the current remains about 41.7 A, still giving 10 kVA total. This confirms the 5 kVA per winding.

The amount of power a transformer secondary can deliver is shared among its windings. When two secondary windings are available, the total secondary kVA is the sum of the kVA ratings of each winding. If the total is 10 kVA and the windings are identical, each one must be able to carry half of that. So each winding is rated at 5 kVA.

For context, at 120 V each winding rated at 5 kVA supports about 41.7 A. If connected in parallel for 120 V, the combined capability is about 83.4 A (10 kVA total). If connected in series for 240 V, the current remains about 41.7 A, still giving 10 kVA total. This confirms the 5 kVA per winding.