$A$ power transformer (step-up) with a $1:8$ turn ratio has $60\, Hz, 120\, V$ across the primary; the load in the secondary is $10^4\ \Omega$. The current in the secondary 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 . . . . . . $A$.

In an ideal step-up transformer, the number of turns in the primary coil and secondary coil are $100$ and $200$ respectively. If the output current is found to be $5 \text{ A}$, then the input current will be . . . . . . . (in $\text{ A}$)

What is increased in a step-down transformer?

$A$ step-down transformer has a turns ratio of $20:1$. If $8 \, V$ is applied across a $0.4 \, \Omega$ secondary coil, then the primary current will be: (in $ \, A$)

$A$ transformer may be used to provide maximum power transfer between two $AC$ circuits that have different impedances $Z_1$ and $Z_2$. The ratio of turns $N_1/N_2$ needed to meet this condition is given by :-