Assume that at the instant the 60 mA dc current source is applied to the circuit in Figure P3, the initial current in the inductor is -45 mA, and the initial voltage on the capacitor is 15 V (positive at the upper terminal). Find the expression for i, (1) for 120 if R equals 200 2. please typing format 60 mA IL (1) 350 mH Figure P3 0.2 μF R

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

Switch S in in the figure is closed at time t = 0, to begin charging an initially uncharged capacitor of capacitance C= 17.9 µF through a resistor of resistance R = 22.7 Q. At what time is the potential across the capacitor equal to that across the resistor? Number i Units S R C

99 Connect a group of identical capacitors first in series and then in parallel. The equivalent capacitance for parallel connections is 100 times larger than for serial connections. How many capacitors are there in this group?