Difficulty: Easy
Correct Answer: Correct
Explanation:
Introduction / Context:
Turns ratio is the defining parameter of an ideal transformer. A step-up transformer increases voltage from primary to secondary; correspondingly, the secondary has more turns than the primary, and the turns ratio N_s/N_p is greater than 1. Recognizing this relationship is key in power conversion and signal coupling.
Given Data / Assumptions:
Concept / Approach:
For an ideal transformer, V_s/V_p = N_s/N_p. Therefore, V_s > V_p requires N_s/N_p > 1. Current ratio inverts: I_s/I_p = N_p/N_s. This captures conservation of power (ignoring losses): V_p * I_p ≈ V_s * I_s.
Step-by-Step Solution:
Verification / Alternative check:
Example: N_p = 100 turns, N_s = 500 turns gives N_s/N_p = 5 and V_s = 5 * V_p, which is a clear step-up case.
Why Other Options Are Wrong:
Common Pitfalls:
Confusing turns ratio with current ratio; assuming core material alters the algebraic ratio rather than efficiency and saturation limits.
Final Answer:
Correct
Discussion & Comments