CH 21-1

Poll Bulb 1 10  20  Bulb 2 Which bulb will be brighter? 1.Bulb 1 2.Bulb 2 3.Neither; they will have the same brightness

Poll 20  Bulb 2 Which bulb will be brighter? 1.Bulb 1 2.Bulb 2 3.Neither; they will have the same brightness Bulb 1 10 

RC Circuit -- Charging the Capacitor At t=0, there is no charge on the capacitor plates and the last wire is connected.

Q vs. t for a charging capacitor Q t

Capacitance

Dielectric Constant

Poll Suppose that a capacitor C 2 has twice the area as another capacitor C 1. Which capacitor can store more charge, if connected to identical batteries? C1C1 C2C2 1.C 1 2.C 2 3.Neither; they can store the same amount of charge.

Poll Suppose that a capacitor C 2 has twice the distance between the plates as another capacitor C 1. Which capacitor can store more charge, if connected to identical batteries? C1C1 C2C2 1.C 1 2.C 2 3.Neither; they can store the same amount of charge.

I vs. t for a charging capacitor I t

 V vs. t for a charging capacitor VV t V bat C R

Poll V bat C R You charge a capacitor using a resistor R. You then discharge it and repeat the experiment, but this time with a resistance of 2R. V bat C 2R 1.It will take more time to fully charge the capacitor. 2.It will take less time to fully charge the capacitor. 3.It will take the same time to fully charge the capacitor.

RC Circuit -- Discharging the Capacitor At t=0, the capacitor plates are charged when the last wire is connected.

Q vs. t for a discharging capacitor Q t

I vs. t for a discharging capacitor I t

 V vs. t for a discharging capacitor VV t V bat C R

Poll C R You discharge a capacitor using a resistor R. You then charge it again and repeat the experiment, but this time connecting a wire across the capacitor (i.e. a short circuit). C 1.It will take more time to fully discharge the capacitor. 2.It will take less time to fully discharge the capacitor. 3.It will take the same time to fully discharge the capacitor.