The capacitive reactance of a capacitor '$$C$$' is $$\mathrm{X} \Omega$$. Both, the frequency of a.c. supply and capacitance of the above capacitor are doubled. The new capacitive reactance will be
A $$100 \mathrm{~mH}$$ coil carries a current of $$1 \mathrm{~A}$$. Energy stored in the form of magnetic field is
A metal rod $$2 \mathrm{~m}$$ long increases in length by $$1.6 \mathrm{~mm}$$, when heated from $$0^{\circ} \mathrm{C}$$ to $$60^{\circ} \mathrm{C}$$. The coefficient of linear expansion of metal rod is
Assume that an electric field $$\mathrm{E}=30 \mathrm{x}^2 \hat{\mathrm{i}}$$ exists in space. If '$$\mathrm{V}_0$$' is the potential at the origin and '$$V_A$$' is the potential at $$x=2 \mathrm{~m}$$, then the potential difference $$\left(\mathrm{V}_{\mathrm{A}}-\mathrm{V}_0\right)$$ is