Norton's theorem states that a complex network connected to a load can be replaced with an equivalent impedance

In the figure shown, the ideal switch has been open for a long time. If it is closed at t=0, then the magnitude of the current (in mA) through the $$4k\Omega$$ resistor at t = 0⁺ is _______.

A series LCR circuit is operated at a frequency different from its resonant frequency. The operating frequency is such that the current leads the supply voltage. The magnitude of current is half the value at resonance. If the values of L, C and R are 1 H, 1 F and 1Ω , respectively, the operating angular frequency (in rad/s) is ________.

In the h-parameter model of the 2-port network given in the figure shown, the value of h₂₂ (in S) is _____ .