A current of 5 A is flowing at 220 V in a primary coil of a transformer. If the voltage produced in the secondary coil is 2200 V and $50 \%$ of power is lost, then the current in the secondary coil will be

Figure shows the combination of inductances and capacitances. Resonant frequency of the $\mathrm{L}-\mathrm{C}$ circuit is

An alternating e.m.f. is given by $e=e_0 \sin \omega t$. In how much time the e.m.f. will have half its maximum value, if e starts from zero ?

$$ \left(\mathrm{T}=\text { Time Period, } \sin 30^{\circ}=\frac{1}{2}\right) $$

A coil has inductance 2 H . The ratio of its reactance when it is connected first to an a.c. source and then to a d.c. source is