6B.2 Charging And Discharging Capacitors

Question 1

how can we investigate the current flow throw a capacitor

Answer 1

by setting up a capacitor in series with a datalogger that senses the current and then charge and discharge the capacitor. this could be done by setting up the circuit in page 46
(note if we log the V by setting up a data sensor parallel to the capacitor)

Question 2

why is using a data logger with a voltage sensor better than a human taking voltage

Answer 2

1. high accuracy
2. prevents shock
3. quick, versatile and save time

Question 3

how can we discharge the circuit found on page 46

Answer 3

by flipping the switch to B as the electrons in the negatively charged side of the capacitor will move to the positive side of it by discharging through the lamp

Question 4

describe the current when discharging throw a lamp

Answer 4

at first, the discharge of electrons would be so fast that the current would be at its most significant and the lamp would light up. after a few electrons are discharged the p.d across the capacitors is weaker and so is the electric field so the push on the electrons is weaker so the current (V/R) weakens and the lamp becomes slightly dimmer, after a long time there is a slight current left so small to the point where the light might appear off, and then finally the capacitator would be fully discharged and the current would be zero

Question 5

what’s the effect of resistance on the current while discharging

Answer 5

it will decrease the rate at which the capacitor discharges. (slowing down the current)

Question 6

what are the three graphs that represent discharging of a capacitor

Answer 6

page 47

Question 7

how can we make a lamp light up longer while discharging, given the same power supply

Answer 7

1. store more charge on the capacitor (by increasing the capacitance (Q=CV)
2. decrease the rate at which the capacitor discharges (by increasing the resistance of the lamp)

Question 8

what is the time constant

Answer 8

it is the measure of the rate for charging and discharging capacitors. it is the time taken for the value of current, change, or voltage of a discharging capacitor to fall to 37% of its initial value

Question 9

how can we calculate the time constant

Answer 9

time constant = RC

Question 10

what an application for the time constant

Answer 10

car courtesy lights use capacitors to discharge current to the bulb for a short period of time, now for some cars, the driver gets to choose how long the light states own and they do that by changing to more or less resistance when discharging the light. so for the same charge, the resistance will be different giving more or less time

Question 11

what are the capacitor charging graphs

Answer 11

page 48

Question 12

the greater the resistance or the larger the charge the

Answer 12

more time it will take to charge/discharge a capacitor