A single phase step-down transformer has a high voltage primary winding and a low voltage secondary winding. The secondary winding is connected to a load impedance $Z_{2}$. The impedance $Z_{2}$ when referred to the primary winding is denoted by $Z_{2}^{\prime}$. Which of the following conditions is true?
- $Z_{2}^{\prime}=Z_{2}$
- $0.5 Z_{2} < Z_{2}^{\prime} < Z_{2}$
- $Z_{2}^{\prime}>Z_{2}$
- $Z_{2}^{\prime} \leq 0.5 Z_{2}$
