Ideal transformer power transfer: If 25 W is applied to the primary of an ideal transformer with turns ratio 10, how much power is delivered to the secondary load?

Introduction / Context:
While the turns ratio changes voltage and current, an ideal transformer conserves power (ignoring losses). This question emphasizes that power in equals power out under ideal conditions, regardless of the ratio value itself.

Given Data / Assumptions:

• Primary input power Pin = 25 W.
• Transformer is ideal (no copper or core loss).
• Turns ratio given but not needed for power equality.

Concept / Approach:
Ideal transformer property: Psecondary ≈ Pprimary. The turns ratio scales voltage and current inversely so that their product remains the same (within small rounding).

Step-by-Step Solution:

Verification / Alternative check:
If voltage is stepped up by 10, current is stepped down by 10, keeping V * I constant, thus preserving power ideally.

Why Other Options Are Wrong:

• 0 W: Would imply open circuit or total loss—contrary to the prompt.
• 250 W or 2.5 W: Misuse the ratio on power instead of on voltage/current.
• 50 W: Would require ≥50% efficiency gain; not applicable.

Common Pitfalls:

• Multiplying or dividing power directly by the turns ratio; only V and I scale with turns.

Final Answer:
25 W