Alternating Cur...

A $$200$$km long telegraph wire has a capacitance of $$0.014$$ $$\mu F/km$$. If it carries an alternating current of $$50\times 10^3$$Hz, what should be the value of an inductance required to be connected in series so that impedance is minimum?

In an L-R circuit, the voltage is given by $$V$$ as $$283 sin 314t$$. The current is found tc be $$4 \, sin \left ( 314t-\dfrac {\pi}{4} \right )$$Calculate the resistance of the circuit. 

A RC series circuit of R$$=15\Omega$$ and $$C=10\mu F$$ is connected to $$20$$ volt DC supply for very long time. Then capacitor is disconnected from circuit and connected to inductor of $$10$$mH. Find amplitude of current.

An L-C-R series circuit containing a resistance of $$R = 120 \Omega $$ has angular resonant frequency $$4 \times 10^5$$ rad/s. At resonance the voltage across resistance and inductance are 60 V and 90 V respectively. Then values of L and C are :

In the circuit diagram shown, $$X_C=100 \Omega,X_L=200 \Omega\, and \, R=100 \Omega$$. Effective current through the source is :

Two parallel wires in the plane of the paper are distance $$X_0$$ apart. A point charge is moving with speed u between the wires in the same plane at a distance $$X_1$$ from one of the wires. When the  wires carry current of magnitude I in the same direction, the radius of curvature of the path of the point charge is $$R_1$$. In contract, if the currents I in the two wires have directions opposite to each other, the radius of curvature of the path is $$R_2$$. If $$\dfrac{X_0}{X_1}=3$$, the value of $$\dfrac{R_1}{R_2}$$ is?

The equivalent inductance between $$A$$ and $$B$$ is:

An alternating voltage given as $$V=100\sqrt { 2 } \sin { 100t } \quad $$is applied to a capacitor of $$1\mu F$$. The current reading of the ammeter will be equal to ______ mA.

An electrical device draws $$2 kW$$ power from ac mains voltage $$223 V(rms).$$ The current differs lags in phase by $$\phi = tan^{-1} \left ( -\dfrac{3}{4} \right )$$ as compared to voltage. The resistance R in the circuit is:

In an oscillating $$LC$$ circuit the maximum charge on the capacitor is $$Q$$. The charge on the capacitor when the energy is stored equally between the electric and magnetic field is