The transformation ratio in a step-up transformer is

$A$ power transmission line feeds input power at $2.3 \text{ kV}$ to a step-down transformer with its primary winding having $3000$ turns. The output power is delivered at $230 \text{ V}$ by the transformer. The current in the primary of the transformer is $5 \text{ A}$ and its efficiency is $90 \%$. The winding of the transformer is made of copper. The output current of the transformer is . . . . . . $A$.

Which of the following is correct for a real transformer?

$A$ power transmission line feeds input power at $2300\; V$ to a step-down transformer with its primary windings having $4000$ turns. What should be the number of turns in the secondary in order to get output power at $230\; V$?

$A$ step-up transformer has a transformation ratio of $3:2$. What is the voltage in the secondary coil if the voltage in the primary coil is $30\, V$?

In a transformer,the number of turns in the primary coil is $140$ and in the secondary coil is $280$. If the current in the primary coil is $4\,A$,then the current in the secondary coil is.....$A$.