Ohm's law recommendation and conclusion
Answers
Answer:
here is your answer
Explanation:
This will be hard to do without doing the experimentation. I guess you will have to "dry lab" the experimental data, which means make up the values. Then conduct your calculations and form a conclusion.
Presumably the lab had several resistors for you to test. Here are the steps you would have taken:
A. Decode the color bands on each resistor to determine the intended resistance and its tolerance (1%, 5%, 10%). For example, if there are 4 bands, the 4th band is the tolerance, the 3rd is the muliplier, and the first two are the base value. Example:
red violet red gold = 2.7kohm, 5% tolerance (That's 2700 ohm.)
Here's a color code calculator:
http://www.hobby-hour.com/electronics/re...
You will do this for each resistor in the set, so make up a set of resitors.
B. Use your instrument to measure the actual resistance. Perhaps it would read as 2793 ohms, not 2700 ohms. (Fabricate this number.) Later, when you do your data analysis, you will calculate the error as:
error = ( (2793-2700)/2700 - 1 ) x 100% = +3.44%
You will do this for each resistor. The calculated percentages should all be different from each other, as would be the case if you measured real-world resistors.
C. To calculate current flow through the resistor, select a voltage V that will be applied across it, then calculate the current using Ohm's law. Let's say you will apply 2.000V. Calculate current I as follows:
I = V/R = 2.000V / 2793 ohm = 0.0007161A = 0.7160mA
You will do this for each resistor.
The instructions don't say to do this next part, but if you really want to show Ohm's law, also calculate the values at other voltages, say 4.000V, 6.000V, 8.000V, and 10.000V. What Ohm's law really says is that an ideal resistor has a linear voltage-amperage relationship. You need multiple points, not just one, to show that the relationship is linear. Five points is a nice number.
[email protected] = 1.432mA
[email protected] = 2.148mA
[email protected] = 2.864mA
[email protected] = 3.580mA
If you don't have time, you can probably skip this paragraph.
D. In the lab, you would place each resistor, one at a time, in series with a variable-voltage power supply and an ammeter. Across the resistor you would connect your voltmeter. If you are using a digital multimeter (DMM) as the voltmeter, the current through it is negligible, so you will assume that the current shown on the ammeter is the current passing through the resistor. Adjust the power supply so that the voltage across the resistor reads 2.000V. Record the voltage and record the current read at the same time on the ammeter. For example, for the first resistor (2793 ohm), the current might read:
[email protected] = 1.434mA
Note that the reading is a little higher than the expected 1.432mA. This would be due to the tolerances associated with the voltmeter, ammeter, and/or ohmeter. In your data analysis, you can calculate this reading as being high by:
( (1.434-1.432)/1.432 -1 ) x 100% = +0.14%
In all of your subsequent current readings, pick ones that are 0.14% higher than the values calculated in step C. The reason for this is that the instrumentation errors usually are consistent and are a fixed percentage. So if one reading shows high, they all will show high.
If you are doing the optional part in step C, then while the first resistor is still in the circuit, increase the voltage to 4.000V and record the current. Then increase to 6.000V, 8.000V, and 10.000V, and do similarly.
Do this for each resistor.
DATA ANALYSIS (Do calculations and then form a conclusion, as follows)
Using the data from steps A and B, you calculate statistical values, such as the mean error and the standard deviation. Your first conclusion from this part might be that the sample set showed actual errors that were less than the indicated tolerance.
Using data from steps C and D, you can do a couple of things. First, show that there was a systematic instrumentation error of 0.14%. Secondly, plot your data of current versus resistance at a fixed voltage of 2.000V. Observe that it is a straight line. You can do a linear regression to fit a straight line to the data, then report the correlation coefficient R. The closer the R value is to 1.0000, the better the data fits a straight line. (R will be less than 1.0000, but close to it).
If you did the optional part, for each resistor, you can plot current versus voltage. Each of these curves should be very close to a straight line. You can perform a similar analysis on it.
Your second conclusion would be that experimental data validates Ohm's Law whereby the current-voltage relationship for a resistor is linear.
please mark as brainliest
Answer:
This will be hard to do without doing the experimentation. I guess you will have to "dry lab" the experimental data, which means make up the values. Then conduct your calculations and form a conclusion.
Presumably the lab had several resistors for you to test. Here are the steps you would have taken:
A. Decode the color bands on each resistor to determine the intended resistance and its tolerance (1%, 5%, 10%). For example, if there are 4 bands, the 4th band is the tolerance, the 3rd is the muliplier, and the first two are the base value. Example:
red violet red gold = 2.7kohm, 5% tolerance (That's 2700 ohm.)
Here's a color code calculator:
http://www.hobby-hour.com/electronics/resistorcalculator.php
You will do this for each resistor in the set, so make up a set of resitors.
B. Use your instrument to measure the actual resistance. Perhaps it would read as 2793 ohms, not 2700 ohms. (Fabricate this number.) Later, when you do your data analysis, you will calculate the error as:
error = ( (2793-2700)/2700 - 1 ) x 100% = +3.44%
You will do this for each resistor. The calculated percentages should all be different from each other, as would be the case if you measured real-world resistors.
C. To calculate current flow through the resistor, select a voltage V that will be applied across it, then calculate the current using Ohm's law. Let's say you will apply 2.000V. Calculate current I as follows:
I = V/R = 2.000V / 2793 ohm = 0.0007161A = 0.7160mA
You will do this for each resistor.
The instructions don't say to do this next part, but if you really want to show Ohm's law, also calculate the values at other voltages, say 4.000V, 6.000V, 8.000V, and 10.000V. What Ohm's law really says is that an ideal resistor has a linear voltage-amperage relationship. You need multiple points, not just one, to show that the relationship is linear. Five points is a nice number.
[email protected] = 1.432mA
[email protected] = 2.148mA
[email protected] = 2.864mA
[email protected] = 3.580mA
If you don't have time, you can probably skip this paragraph.
D. In the lab, you would place each resistor, one at a time, in series with a variable-voltage power supply and an ammeter. Across the resistor you would connect your voltmeter. If you are using a digital multimeter (DMM) as the voltmeter, the current through it is negligible, so you will assume that the current shown on the ammeter is the current passing through the resistor. Adjust the power supply so that the voltage across the resistor reads 2.000V. Record the voltage and record the current read at the same time on the ammeter. For example, for the first resistor (2793 ohm), the current might read:
[email protected] = 1.434mA
Note that the reading is a little higher than the expected 1.432mA. This would be due to the tolerances associated with the voltmeter, ammeter, and/or ohmeter. In your data analysis, you can calculate this reading as being high by:
( (1.434-1.432)/1.432 -1 ) x 100% = +0.14%
In all of your subsequent current readings, pick ones that are 0.14% higher than the values calculated in step C. The reason for this is that the instrumentation errors usually are consistent and are a fixed percentage. So if one reading shows high, they all will show high.
If you are doing the optional part in step C, then while the first resistor is still in the circuit, increase the voltage to 4.000V and record the current. Then increase to 6.000V, 8.000V, and 10.000V, and do similarly.
Do this for each resistor.
DATA ANALYSIS (Do calculations and then form a conclusion, as follows)
Using the data from steps A and B, you calculate statistical values, such as the mean error and the standard deviation. Your first conclusion from this part might be that the sample set showed actual errors that were less than the indicated tolerance.
Using data from steps C and D, you can do a couple of things. First, show that there was a systematic instrumentation error of 0.14%. Secondly, plot your data of current versus resistance at a fixed voltage of 2.000V. Observe that it is a straight line. You can do a linear regression to fit a straight line to the data, then report the correlation coefficient R. The closer the R value is to 1.0000, the better the data fits a straight line. (R will be less than 1.0000, but close to it).
If you did the optional part, for each resistor, you can plot current versus voltage. Each of these curves should be very close to a straight line. You can perform a similar analysis on it.
Your second conclusion would be that experimental data validates Ohm's Law whereby the current-voltage relationship for a resistor is linear.