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Voltage Divider Circuits
37 questions By Tony R. Kuphaldt
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Question 22 of 37
A student builds the following voltage divider circuit so she can power a 6-volt lamp from a 15-volt power supply:
When built, the circuit works just as it should. However, after operating successfully for hours, the lamp suddenly goes dark. Identify all the possible faults you can think of in this circuit which could account for the lamp not glowing anymore.
Reveal answerHere are a few possibilities (by no means exhaustive):
- Lamp burned out
- 15-volt power supply failed
- Resistors R1 and R2 simultaneously failed open
Follow-up question: although the third possibility mentioned here is certainly valid, it is less likely than any single failure. Explain why, and how this general principle of considering single faults first is a good rule to follow when troubleshooting systems.
Notes:Have fun with your students figuring out all the possible faults which could account for the lamp going dark! Be sure to include wires and wire connections in your list.
The follow-up question is intended to get students to come up with their own version of Occam’s Razor: the principle that the simplest explanation for an observed phenomenon is probably the correct one.
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Question 23 of 37
One of the resistors in this voltage divider circuit is failed open. Based on the voltage readings shown at each load, determine which one it is:
Reveal answerResistor R1 has failed open.
Notes:Discuss with your students how they were able to predict R1 was the faulty resistor. Is there any particular clue in the diagram indicating R1 as the obvious problem?
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Question 24 of 37
One of the resistors in this voltage divider circuit is failed open. Based on the voltage readings shown at each load, determine which one it is:
Reveal answerResistor R2 has failed open.
Notes:Discuss with your students how they were able to predict R2 was the faulty resistor. Is there any particular clue in the diagram indicating R2 as the obvious problem?
Plus signs are missing from these questions and answers, such as in question 11, where the denominator of the voltage divider equation appears as “R1 R2 R3” instead of “R1+R2+R3”. Same in the answer to question 15. Likely elsewhere as well, as Find shows no results for “+” anywhere on the page. I’m using Chrome 88.0.4324.182 on Windows 10, but same on Firefox & Edge. HTML source for the page shows it as “R1 R2 R3”, so it isn’t just a display problem.
Iam a student and i need an explain for this answers how can I get an explanation ?
Ca any one tell in detail how
The formula got formed like this !! ( ER= Et(R/Rt)) thank you