Exercise

There are two circuits, one with pure inductive load and the other with pure capacitive load. What is the net power absorbed by each circuit over a complete cycle. Explain your answer.

The RMS value of current in an ac circuit is $10 \mathrm{A}$. What is the peak current?

A transformer works on the principle of

The ratio of currents in primary and secondary coils of a transformer with $100\%$ efficiency is $1:4$, the ratio of the voltage across the coils will be-

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

A small town with a demand of $800 \mathrm{kW}$ of electric power at $220 \mathrm{V}$ is situated $15 \mathrm{km}$ away from an electric plant generating power $440 \mathrm{V}$. The resistance of the two wire line carrying power is $0.5 \mathrm{\Omega }$ per km. The town gets power from the line through a $4000-220 \mathrm{V}$ step down transformer at a substation in the town. (a) Estimate the power loss in the form of heat. (b) How much power must the plant supply, assuming there is negligible power loss due to leakage? (c) Characterise the step -up transformer at the plant.

A small town with a demand of $800 \mathrm{kW}$ of electric power at $220 \mathrm{V}$ is situated $15 \mathrm{km}$ away from an electric plant generating power $440 \mathrm{V}$. The resistance of the two wire line carrying power is $0.5 \mathrm{\Omega }$ per km. The town gets power from the line through a $40000-220 \mathrm{V}$ step down transformer at a substation in the town. (a) Estimate the power loss in the form of heat. (b) How much power must the plant supply, assuming there is negligible power loss due to leakage? (c) Characterize the step -up transformer at the plant.

A capacitor, resistor of $5 \mathrm{\Omega }$ and an inductor of $50 \mathrm{m}\mathrm{H}$ are in series with an AC source marked $100 \mathrm{V}, 50 \mathrm{H}\mathrm{z}$. It is found that voltage is in phase with the current. Calculate the impedance of the circuit.