Elenco's PK-201 Experiment #9: Small Dominates Large -- Capacitors in Series

In this experiment, capacitors in a series combine to make a smaller circuit capacitance. Here I am using two capacitors (100 and 10 microfarads) in series. Below the video is the formula for calculating capacitance for two or more capacitors in a series.

 

 

Good Study Aid

 



Elenco's PK-201 Experiment #8: Slow Light Bulb

This experiment demonstrates the charging and discharging of a capacitor. The charge/discharge time is controlled by resistors on either side of the capacitor. These resistors control the flow of electricity going to the capacitor (charge) and from the capacitor (discharge). The discharge is visualised by the LED in the experiment. The slower the LED dims, the larger the resistor is (ohms) that is controlling the discharge from the capacitor. The charge/discharge times are proportional to both the capacitance (amount of voltage a capacitor can hold) and the resistance in the charge/discharge path. In the below videos titles, the numbers followed by K are the charge and discharge resistor values (respectively), and the last number is the capacitor's capacitance in micro farads.

 

 

 

 

 

 

Elenco's PK-201 Experiment #7: Water Detector

This experiment shows that water will conduct electrical current. But, resistance can vary by amount and purity of the water. In the first picture, tap water is used to conduct electrical current. The LED is dimly lit because the water has a high resistance. In the last picture, salt was added to the same water causing the LED to become brightly lit. To conclude, water will conduct electrical current, but pure water has a higher resistance then water with salt dissolved in it.

Fresh Water (Dim LED)

No Water (off LED)

Salt Water (Bright LED)

Water and Electrical Conduction

Elenco's PK-201 Experiment #6: Combined Circuit

In this experiment there are two LED's (Left and Right). The left LED is connected to a 3.3k ohms resister, and, in addition, to a variable resistor (0 to 50k ohms). The left LED is connected only to a 10k ohms resistor. The first picture, shows a lighted left LED and a very dim right LED because most of the current is flowing in the direction of least resistance. The variable resistor is set to 0 ohms, which leaves only a resistance of 3.3k ohms. Where as the right LED has a higher resistance of 10k ohms. The second picture, shows both LED's lighted because the Variable resistor is set to give equal resistance as the right LED (10k ohms) resistance. In the last picture, the right LED is the brightest because the variable resistor is set to the maximum resistance of 50k ohms. Like experiment #5 current is still flowing in multiple paths, but nearly all the current is flowing towards the path of least resistance.  



Current is flowing through left LED

Equal resistance current is divided between both LEDs

Current is flowing through right LED

Further Study:
Questions and Answers on Physics
What is a Parallel Circuit?
 

Elenco's PK-201 Experiment #5: Comparison of Parallel Currents

This experiment is demonstrating that current can move along multiple paths in a circuit. More over, that the current is proportional to the resistance of said circuit.

100k ohm resistor

1k ohm resistor

10k ohm resistor

More Information

Elenco's PK-201 Experiment #4: Parallel Pipes

In general, this experiment shows that the more resistors that are in parallel in a circuit, the lower the total resistance; subsequently, more current will flow through the circuit. The formula and calculations are at the bottom showing the total resistance in each example.

3.2k ohm's

2.5k ohm's

770 ohm's
 

More information
Resistor 

Elenco's PK-201 Experiment #3: Resistors In Series

Resistors in a series add together to increase the total resistance of a circuit. In addition, the larger resistor in that series will control the flow of current in said circuit.

3.3k and 100k ohm resistors = 103.3k ohms

3.3k and 10k ohm resistors = 13.3k ohms

3.3k and 1k ohm resistors = 4.3k ohms