In an ideal transformer, the secondary voltage is determined by the turns ratio. If the secondary has half as many turns as the primary, the secondary voltage is

In an ideal transformer, the secondary voltage is determined by the turns ratio. If the secondary has half as many turns as the primary, the secondary voltage is

• A. Directly proportional to the turns ratio
• B. Half as large
• C. Twice as large
• D. One quarter as large

Answer: (B)

In an ideal transformer, the voltage on the secondary scales with the turns ratio: Vs = Vp × (Ns/Np). If the secondary has half as many turns as the primary, Ns/Np = 1/2, so the secondary voltage is Vp/2. In other words, it is half of the primary voltage. (If power is conserved, the secondary current would double to balance the voltage change.)

In an ideal transformer, the voltage on the secondary scales with the turns ratio: Vs = Vp × (Ns/Np). If the secondary has half as many turns as the primary, Ns/Np = 1/2, so the secondary voltage is Vp/2. In other words, it is half of the primary voltage. (If power is conserved, the secondary current would double to balance the voltage change.)