The inductive reactance of a coil is R$$\Omega$$. If the inductance of a coil is doubled and frequency of a.c. supply is also doubled then the new inductive reactance will be

Three pure inductors each of inductance 6H are connected as shown in the figure. Their equivalent inductance between the points 'P' and 'Q' is

The instantaneous value of an alternating current is given by $$\mathrm{i}=50 \sin (100 \pi \mathrm{t})$$. It will achieve a value of $$25 \mathrm{~A}$$ after a time interval of $$\left(\sin 30^{\circ}=0.5\right)$$

In a step up transformer, which one of the following statements is correct?