$A$ transformer consisting of $300$ turns in the primary and $150$ turns in the secondary gives output power of $2.2\, kW$. If the current in the secondary coil is $10\, A$,then the input voltage and current in the primary coil are

$A$ step-up transformer operates on a $230\, V$ line and supplies a load of $2\, A$. The ratio of the primary and secondary windings is $1 : 25$. The current in the primary is.... (in $, A$)

The primary of a transformer has $100$ turns and operates at $100 \,V - 200 \,W$. The number of turns in the secondary,if the output voltage is $2000 \,V$,is:

$A$ small town with a demand of $900 \text{ kW}$ of electric power at $220 \text{ V}$ is situated $20 \text{ km}$ away from an electric power generating station. The two-wire line has a resistance per unit length of $5 \times 10^{-4} \text{ } \Omega \text{ m}^{-1}$. The town gets power from the line through a $45000 \text{ V}$ to $220 \text{ V}$ step-down transformer at a substation in the town. The line power loss in the form of heat is: (in $text{ kW}$)

$A$ step-up transformer connected to a $220 \,V$ $AC$ line is to supply $22 \,kV$ for a neon sign in the secondary circuit. In the primary circuit,a fuse wire is connected which is to blow when the current in the secondary circuit exceeds $10 \,mA$. The turns ratio of the transformer is:

Large transformers,when used for some time,become hot and are cooled by circulating oil. The heating of a transformer is due to: