Consider the circuit shown.
Let V = 50 V, R1 = 10 Ω, R2 = 100 Ω, and L = 50 H.
All circuit elements are ideal and no current flows before the switch is
closed.
(a) After the switch is closed at t = 0, find the current I flowing through
the switch as a function of time.
(b) After 8 s the switch is opened again. Right after the switch is opened,
what is the voltage across R2 and across the switch?
An AC source provides a voltage with amplitude 230 V with frequency 50 Hz. A circuit contains one coil, two same capacitors and a resistor connected as shown in the figure. All circuit elements have an unknown impedance. With the switch open, the voltage lags behind current of the generator by 20o. If the switch is in the position 1, the voltage leads the current of by 20o. With the switch is in position 2, the current in the circuit has amplitude 2 A.
Find the resistance of the resistor, the inductance of the coil and the capacitance of the
capacitor.
Consider the impedance bridge shown in the figure below. Its purpose is to permit
measurements of an unknown impedance Zu in terms of the fixed
resistance RA and RB, variable resistance RS
and variable capacitance CS. If Zu is a pure
resistance, then CS may be removed from the circuit (shorted out) and
the impedance bridge becomes a simple Wheatstone bridge.
(a) For a purely resistive impedance Zu find the value of RS
for which a balance is obtained (no current on the null detector).
(b) For a complex impedance Zu whose resistive component is Ru
and whose reactive component is Xu, find the values of RS
and CS for which balance is obtained. Assume Zu has
zero inductance.
(c) Show that for a purely inductive component Zu balance is
not possible.
A 10 μF capacitor that is initially uncharged is connected in series with a 5 Ω resistor and an emf source with ε = 50 V and negligible internal resistance. At the instant when the energy stored in the capacitor is 5*10-4 J, what is the rate at which the resistor is dissipating electrical energy.