The rms voltage output of a generator is $220 \mathrm{V}$. The coil is square of side $20.0 \mathrm{cm}$, has $300$ turns of wire and rotates at $50$revolutions per second. What is the magnetic field? 

The graph shows the variation, with time, of the magnetic flux linkage through a loop. What is the rms value of the emf produced in the loop?

A power station produces$150 \mathrm{kW}$ of power, which is transmitted along cables of total resistance $2.0 \Omega$. What percentage of the power is lost if it is transmitted at $1000 \mathrm{V}$.

A power station produces$150 \mathrm{kW}$ of power, which is transmitted along cables of total resistance $2.0 \mathrm{\Omega }$. What percentage of the power is lost if it is transmitted at $5000 \mathrm{V}$.

Calculate the average power dissipated in a $24 \Omega$ resistor that is connected in series to a source of a.c voltage of peak value $140 \mathrm{V}$.