The correct answer is option 'C' - the statement that the leakage reactance has a non-zero value is not true for an ideal transformer.

Explanation:
An ideal transformer is a theoretical concept used in electrical engineering to simplify calculations and analysis. It is assumed to have certain characteristics that do not exist in real transformers but help in understanding and solving problems related to transformers.

1. Zero iron loss:
In an ideal transformer, the iron loss is assumed to be zero. Iron loss refers to the energy dissipated in the iron core of the transformer due to hysteresis and eddy currents. In reality, there is always some energy loss associated with the magnetic properties of the core material. However, for the purpose of analysis, an ideal transformer assumes zero iron loss.

2. Zero winding resistance:
The winding resistance of an ideal transformer is considered to be zero. Winding resistance is the resistance offered by the copper windings of the transformer. In real transformers, this resistance can cause power loss and affect the efficiency of the transformer. But in an ideal transformer, the winding resistance is neglected to simplify calculations.

3. Non-zero leakage reactance:
The leakage reactance represents the reactance caused by the leakage flux in a transformer. It is a result of imperfect magnetic coupling between the primary and secondary windings. In an ideal transformer, the leakage reactance is assumed to be zero. This assumption is made to simplify the analysis and calculations. However, in real transformers, there is always some leakage reactance that affects the performance and efficiency of the transformer.

4. Zero magnetizing current:
The magnetizing current of an ideal transformer is assumed to be zero. Magnetizing current is the current required to establish the magnetic field in the transformer core. In reality, there is always some magnetizing current needed to magnetize the core. However, for the purpose of analysis, an ideal transformer assumes zero magnetizing current.

In summary, an ideal transformer assumes zero iron loss, zero winding resistance, zero magnetizing current, and zero leakage reactance. Among these assumptions, the statement that the leakage reactance has a non-zero value is not true for an ideal transformer.