(a) (i) Write the principle of working of an ac generator. Draw its labelled diagram and explain its working. (ii) A resistor of $400\text{ }\Omega$, an inductor of $\left$\frac{5}{\pi}\right$\text{ H}$ and a capacitor of $\left$\frac{50}{\pi}\right$\text{ }\mu\text{F}$ are joined in series across an ac source $\text{v} = 140\text{ sin}$100\pi$\text{t V}$. Find the rms voltages across these three circuit elements. The algebraic sum of these voltages is more than the rms voltage of source. Explain. OR (b) (i) Write the principle of working of a transformer. With the help of a labelled diagram, explain the working of a step-up transformer.