The output power in a step-up transformer used in practice is . . . . . .

$A$ $220\, V$ input is supplied to a transformer. The output circuit draws a current of $2.0\, A$ at $440\, V$. If the efficiency of the transformer is $80\%$,the current drawn by the primary windings of the transformer is ..... $A$.

In a transformer,$220 \ V$ $AC$ voltage is increased to $2200 \ V$. If the number of turns in the secondary coil is $2000$,then the number of turns in the primary coil will be:

In a step-up transformer, the turn ratio is $1:10$. A resistance of $200 \, \Omega$ connected across the secondary is drawing a current of $0.5 \, A$. What is the primary voltage and current?

$1\, MW$ power is to be delivered from a power station to a town $10\, km$ away. One uses a pair of $Cu$ wires of radius $0.5\, cm$ for this purpose. Calculate the fraction of ohmic losses to power transmitted if
$(a)$ power is transmitted at $220\, V$. Comment on the feasibility of doing this.
$(b)$ a step-up transformer is used to boost the voltage to $11000\, V$,power is transmitted,then a step-down transformer is used to bring voltage to $220\, V$.
Given: $\rho_{Cu} = 1.7 \times 10^{-8}\, \Omega \cdot m$.

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