Can the potential difference between the terminals of a battery ever be opposite in direction to the emf? If it can, give an example. If it cannot, explain why not.

10MF 4) Find how much time elapses before the charge on each capacitor reach 1/3 of the maximum value once the switch is closed, if R = 100 kohms. 3V R 10pF

Problem 10: While preparing a laboratory experiment on capacitors, you connect an E-4.5 V DC power supply to fully charge an old capacitor that is marked C- 330 HF Your lab assistant hooks up the circuit as shown below. When the switch S is at point a, the capacitor is connected to the power supply. When the switch S is at point b, the capacitor is disconnected from the power supply and connected to a voltmeter, V. The voltmeter has an internal resistance R-10.0 MS2 al Otheexpertta.com Part (a) The capacitor is initially uncharged, when the switch is moved to position a, hooking the capacitor C to the power supply. What will happen to the charge on the capacitor? It will quickly (but not instantaneously) increase to a maximum value Correct! Part (b) Calculate the charge on the capacitor (in Coulombs) when it is fully charged by the power supply Part (c) After the capacitor is fully charged, you switch the switch to position b at time t-0 seconds. The voltmeter initially reads 4.5 V.…

A parallel plate capacitor used in a flash for a camera must be able to store 16.0 J of energy when connected to 309 V. (Most electronic flashes actually use a 1.50- to 6.00-V battery, but increase the effective voltage using a dc–dc inverter.)     What should be the capacitance of this capacitor?