Consider the circuit shown in the figure with input V(t) in volts. The sinusoidal steady state current I(t) flowing through the circuit is shown graphically (where t is in seconds). The circuit element Z can be _________.

A linear 2-port network is shown in Fig. (a). An ideal DC voltage source of 10 V is connected across Port 1. A variable resistance R is connected across Port 2. As R is varied, the measured voltage and current at Port 2 is shown in Fig. (b) as a V₂ versus $$-$$I₂ plot. Note that for V₂ = 5 V, I₂ = 0 mA, and for V₂ = 4 V, I₂ = $$-$$4 mA. When the variable resistance R at Port 2 is replaced by the load shown in Fig. (c), the current I₂ is ________ mA (rounded off to one decimal place).

The Fourier transform X(j$$\omega$$) of the signal $$x(t) = {t \over {{{(1 + {t^2})}^2}}}$$ is ____________.

Let x₁(t) = e^$$-$$t u(t) and x₂(t) = u(t) $$-$$ u(t $$-$$ 2), where u( . ) denotes the unit step function. If y(t) denotes the convolution of x₁(t) and x₂(t), then $$\mathop {\lim }\limits_{t \to \infty } y(t)$$ = __________ (rounded off to one decimal place).