The ABCD parameters of an ideal n:1 transformer shown in Fig. are $$\left[ {\matrix{ n & 0 \cr 0 & X \cr } } \right]$$. The value of X will be

For the circuit in figure, the phase current $${{\rm I}_1}$$ is

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

If R₁ = R₂ = R₄ = R and R₃ = 1.1R in the bridge circuit shown in figure, then the reading in the ideal voltmeter connected between a and b is