Voltage Divider: Calculating Output Voltage

In summary, a voltage divider with two 56kohm resistors and a 15V source was discussed. The formula for calculating the unloaded output voltage across one of the resistors was derived by using the total current and voltage division. Drawing pictures was suggested as a helpful tool for understanding the problem and seeking assistance. It was also emphasized that asking for help with understanding the question is more beneficial than asking for someone to do the homework.
  • #1
jodi32
1
0
1. Homework Statement A voltage divider consists of two 56kohms resistors and a 15V source. Calculate the unloaded output voltage taken across one of the 56kohm resistors. What will the output voltage be if a load resistor of 1.0Mohms is connected across the output?
 
Physics news on Phys.org
  • #2
For the first part, do you know how to calculate the total current flowing through the two resistors? If so, what would that make the voltage across one of the resistors? If you symbolically do these two things, you'll derive the commonly used "voltage division" formula
 
  • #3
Drawing pictures generally helps you understand the question, and helps people see what you're talking about (if you write the question and draw a picture and get the picture wrong, people can also help your interpretation of the question into a picture). Heres one I drew in ms paint in less than a minute.

Making an attempt at the question or outlining what the problem is or what you don't understand also helps people help you, as generally people will not do your homework for you, but rather try to steer you in the right direction towards completing it for yourself (much more satisfying).
 

Attachments

  • Voltage Divider Part A.JPG
    Voltage Divider Part A.JPG
    8.7 KB · Views: 355

1. What is a voltage divider?

A voltage divider is a circuit that divides a voltage into smaller, proportional voltages. It is typically made up of two resistors in series, with the output voltage taken between the two resistors. The ratio of the two resistors determines the output voltage.

2. How do you calculate the output voltage of a voltage divider?

The output voltage of a voltage divider can be calculated using the formula Vout = Vin * (R2 / (R1 + R2)), where Vin is the input voltage and R1 and R2 are the resistances of the two resistors in the divider.

3. Can a voltage divider be used to step down a voltage?

Yes, a voltage divider can be used to step down a voltage by using resistors with appropriate values. The output voltage will be a fraction of the input voltage, depending on the ratio of the resistors.

4. What is the purpose of using a voltage divider?

A voltage divider is used to reduce a voltage to a desired level, for example, to provide a lower voltage to a sensitive component or to measure a high voltage with a lower range voltmeter. It is also commonly used in electronic circuits to bias transistors or set reference voltages.

5. Are there any limitations or drawbacks of using a voltage divider?

One limitation of using a voltage divider is that the output voltage is affected by changes in the input voltage. Additionally, the use of high-value resistors can introduce errors due to the tolerance of the resistors and the effects of leakage currents. It is important to carefully select resistor values and consider these factors when designing a voltage divider circuit.

Similar threads

  • Engineering and Comp Sci Homework Help
Replies
8
Views
2K
  • Engineering and Comp Sci Homework Help
Replies
17
Views
1K
  • Engineering and Comp Sci Homework Help
Replies
1
Views
1K
  • Engineering and Comp Sci Homework Help
Replies
12
Views
2K
  • Engineering and Comp Sci Homework Help
Replies
7
Views
893
  • Engineering and Comp Sci Homework Help
Replies
3
Views
814
  • Engineering and Comp Sci Homework Help
Replies
34
Views
2K
  • Engineering and Comp Sci Homework Help
Replies
13
Views
2K
  • Engineering and Comp Sci Homework Help
Replies
5
Views
1K
  • Engineering and Comp Sci Homework Help
Replies
10
Views
1K
Back
Top