For the circuit in Figure 3 the switch is in the left position for several minutes: (a) Find the Initlal voltage, Vo on the capacitor just before the switch is flipped (b) Find an expresslon v(t) that describes the voltage across the 20 2 resistor after the switch has been flipped to the right NOTE: Remember what we said in class: use a Circuit-Specific Equation to get a value you know. Then solve for whatever else the problem asks for

A 500 nF capacitor is connected in series with a 100 kohm resistor and the circuit is connected to a 50V, d.c. supply. Calculate the initial value of current flowing, the value of current 150 ms after connection, the value of capacitor voltage 80 ms after connection, and the time after connection when the resistor voltage is 35 V.

In the diagram below, the switch S has been closed for a long time. A) What is the output voltage Vout? What is the charge on the capacitor? b) The switch is opened, so the output voltage increases. What is the time constant that describes the charging of the capacitor in terms of R and C? c) When Vout reaches 10 V, the switch closes and the capacitor begins to discharge. What is the time constant that describes the discharging in terms of R and C? Hint: Apply Kirchhoff's Rules to both loops and the sum of the currents at the junction above the capacitor in the diagram, and use I=dq/dt. If the switch opens when Vout reaches a lower value, say 5V, the capacitor will charge again, and thus one can cycle the voltage with a time constant determined by the circuit: this demonstrates the principle of operation of an electronic timer. 4R S 15 V Vout R

A battery is used to charge a capacitor through a resistor as shown in the following figure. After the switch is closed the energy supplied by the batteryis E. Find the Joule heat produced in the resistor and the energy which is stored in the capacitor.