The RC circuit shown in the figure is

In a series $$RLC$$ circuit $$R = 2\,k\Omega ,\,\,\,L = \,1H$$ and $$C = \,1/400\,\mu F.$$ The resonant frequency is

The circuit shown in figure, with $$R = 1/3\Omega $$, $$L = 1/4H$$, $$C = 3F$$ has input voltage $$v\left( t \right) = \sin \,2t$$. The resulting current $$i(t)$$ is

For the circuit shown in figure, the time constant $$RC = 1$$ $$ms$$. The input voltage is $${v_i}\left( t \right) = \sqrt 2 \,\sin \,{10^3}t$$. The output voltage $${v_0}\left( t \right)$$ is equal to