A circuit is set up as below, we were asked to predict what happens when the switch is closed. Before the switch closed, the bulb marked 1 and 3 was lit and the bulb marked 2 was off when the switch was opened. After the switch is closed, nothing changed. We found iut that there is no effect on the middle path when there is a closed circuit around it. This is called short circuit.
We are then given a different setup as shown on the left bottom.
We make a table of what makes the difference in brightness between the bulb and the battery. When the circuit is arranged in series, the bulb is dimmer, and when it's arranged in parallel, the bulb is brighter, whereas the battery is the opposite. When the circuit is arranged in series, the battery is brighter, and when it's arranged in parallel, the battery is dimmer.
This brightness is affected by both, current and voltage. From the equation we learned before, power is current multiplied by voltage. These two gives what we know as Watt, which is the Power.
Understanding How to Read Resistor:
There are 3 or 4 lines in resistor. These lines are the color coding of how much resistance does it have. Each color has its own value. When we are reading the resistor color, first and second band are put together as the first and second number of the resistance value (sometimes third band too if the resistor has five lines), the second line from the last is the multiplier of the resistance value, so it will be 10 to the power of that color's value. The last line shows the uncertainty of that resistance in percentage.We are then given 4 resistors and try to read each resistor value by its color coding. After doing so, we tested their resistence with the multimeter.
The first resistor, by color coding is found to be 1200 ohm with uncertainty of 5% and was tested to be 1256, which was in the range of the uncertainty, so this was correct. The second resistor, by color coding is found to be 20 x 10 ohm with uncertainty of 5% and was tested to be 198.6, which was in the range of the uncertainty, so this was correct. The third resistor, by color coding is found to be 30 x 10^2 ohm with uncertainty of 5% and was tested to be 3060, which was in the range of the uncertainty, so this was correct. The forth resistor, by color coding is found to be 33 ohm with uncertainty of 5% and was tested to be 40.8, This was slightly off because it was not in the range of the uncertainty. This may be due to ...
Given 3 resistors, we want to set it up in different arrangements. First, we want to find the resistance of 1 resistor, which is foun to be 612 ohm. Then, we want to attach another resistor next to it and find the resistance of both to be 1225 ohm. Attaching another resistor, we found the resistance to be 1835 ohm.
Next, we want to take them all apart and attach one of the resistor on top of the first one instead of next to it and find the resistance using multimeter. When we place the multimeter needle in between the two resistors, we found the resistance to be 306 ohm. Then, we add more resistor parallel to the two resistors. We found the resistance to be 204 ohm.
From these data, we can conclude that in series, the resistances are added, whereas in parallel, the resistances are divided depending on how many resistors there are.
Understanding Equation of Resistance:
When in parallel, the equation of resistance will be 1/Req=1/R1+ 1/R2. When in series, the equation of resistance will be the sum of all resistance.Given the mixture of parallel and series in a circuit as below, we have to separate each of them. Start by adding the series first. The top series resistance will give the sum of both, which results in 320 ohm. Then calculate the parallel of that part, this gives about 76 ohm. Then add it with the series next to it, which results in about 176 ohm. Then we calculate the bottom parallel, which gives the out resistance to be 110 ohm. The last resistance is in parallel. Using the parallel equation, we found the final resistance to be about 70 ohm.
Understanding Kirchoff's Law:
No comments:
Post a Comment