In a series RC circuit composed of a resistance R, a capacitor, and an emf source, the energy stored in the capacitor decreases with time as the capacitor discharges. After how many time constants is this stored energy one-fifth its initial value? A) 0.55 B) 1.04 C) 0.80 D) 0.90 E) 0.35

Why do power lines near your home contain transformers? A Transformers increase the current flowing into your home. B The transformers reduce the voltage to a level the wires in your house can safely carry. C The transformers increase the voltage supplied to your home during peak usage times. D Transformers decrease resistance in the power lines.

A fully charged capacitor with capacitance of C= 80 uF is being discharged. If the total electric resistance of the circuit is 24.0 k and the initial voltage of capacitor is V=10 V, then: a) How long does it take for the capacitor to discharge by 70%? b) Calculate the energy lost from the capacitor by this time? c) Calculate the heat energy produced in the resistor by this time. d) Are the values of energies in parts c and d expected to be the same? Explain.

The Q vs t graph shown below is for the capacitor of an RC circuit. Q (C) 10 7.5 5. 2.5 7 14 21 28 35 42 49 56 63 70 t(s) Determine the time constant of the RC circuit. TH If R= 802, determine C. C= MY NOTES

V = 60.0 V R = 13.0 k C = 16.0 με simple RC circuit The moment after this circuit is connected, when the capacitor is fully uncharged, the current in the circuit is A very long time after the circuit is connected, when the capacitor is fully charged, the charge on the capacitor is mA. C.

A series RC circuit with C = 48 mF and R = 50 Ω is driven by a 24 V source. With the capacitor initially uncharged, an open switch in the circuit is closed to complete the circuit. What is the voltage across the capacitor immediately after the switch is closed? What is the voltage across the resistor immediately after the switch is closed? What is the current in the resistor immediately after the switch is closed? What is the voltage across the capacitor after the switch has been closed for 1 s? What is the voltage across the resistor after the switch has been closed for 1 s? What is the current in the resistor after the switch has been closed for 1 s?

2. A 0.30-m-long metal bar is moving to the left at constant speed of 20 m/s perpendicular to a uniform 2.0 T magnetic field. The bar rides on parallel metal rails connected through a 6.00 resistor, so the apparatus makes a complete circuit, as shown in the figure below. Ignore the resistance of the bar and the rails.

In an RC circuit, if we change the resistance to one with a higher value, we would expect that: A. The area under the curve changes B. Capacitor discharges faster C. The capacitor takes longer to achieve Q max D. Change the Vc voltage when the capacitor charges