In an ideal transformer, how does the primary voltage relate to the secondary voltage in terms of turns ratio Np:Ns?

In an ideal transformer, how does the primary voltage relate to the secondary voltage in terms of turns ratio Np:Ns?

• A. Vp/Vs = Ns/Np
• B. Vp/Vs = Np/Ns
• C. Vp/Vs = Np+Ns
• D. Vp/Vs = 1

Answer: (B)

Voltage in an ideal transformer scales with the number of turns on each winding. Because the same changing magnetic flux links both windings, the induced EMF in a winding is proportional to its number of turns. Therefore the primary-to-secondary voltage ratio equals the turns ratio: Vp/Vs = Np/Ns. If the primary has more turns, the primary voltage is higher; if the secondary has more turns, the secondary voltage is higher. In an ideal transformer, power conservation also holds: Vp Ip = Vs Is, which aligns with this voltage relationship. The idea that the ratio would be a sum or the reciprocal doesn’t describe how voltages relate to turns.

Voltage in an ideal transformer scales with the number of turns on each winding. Because the same changing magnetic flux links both windings, the induced EMF in a winding is proportional to its number of turns. Therefore the primary-to-secondary voltage ratio equals the turns ratio: Vp/Vs = Np/Ns. If the primary has more turns, the primary voltage is higher; if the secondary has more turns, the secondary voltage is higher. In an ideal transformer, power conservation also holds: Vp Ip = Vs Is, which aligns with this voltage relationship. The idea that the ratio would be a sum or the reciprocal doesn’t describe how voltages relate to turns.