- #1
Cici2017
Homework Statement
Homework Equations
The Attempt at a Solution
Can someone tell me what formula to use? Is it p=RA/L? but what about the mass? Thanks~
Resistance of a cylindrical resistor
- Thread starter Cici2017
- Start date
Click For Summary
SUMMARY
The discussion centers on the resistance of cylindrical resistors, specifically addressing the formula for resistivity, p = RA/L, where R is resistance, A is cross-sectional area, and L is length. Participants emphasize the importance of physical understanding over rote memorization of formulas, suggesting that conceptualizing the resistor's properties through thought experiments can enhance comprehension. The relationship between mass, volume, and resistivity is also explored, with the formula p = m/V being referenced to illustrate these concepts.
PREREQUISITES- Understanding of resistivity and its formula p = RA/L
- Basic knowledge of geometric properties of cylinders, specifically volume V = πr²L
- Familiarity with mass and volume relationships in physics
- Ability to perform thought experiments to conceptualize physical principles
- Study the derivation and application of the resistivity formula p = RA/L
- Explore the geometric properties of cylinders and their impact on electrical resistance
- Investigate the relationship between mass, volume, and resistivity in different materials
- Learn about thought experiments in physics to enhance conceptual understanding
Students studying electrical engineering, physics enthusiasts, and educators looking to deepen their understanding of resistor behavior and resistance concepts.
Can someone tell me what formula to use? Is it p=RA/L? but what about the mass? Thanks~
- #2
Dadface
- 2,489
- 105
What can you infer about the volume of the smaller resistors compared to the volume of the larger resistor?
- #3
Cici2017
p=m/V ,Dadface said:
if m half, V half,
V=πr2L
right?
- #4
epenguin
Science Advisor
- 3,637
- 1,013
Cici2017 said:
I will tell you don't use any formula. It will do you no good, maybe less than none. Use physical thinking. Use a thought experiment like slicing a resistor in two.
Get the physical understanding then that will help you understand the formula!
- #5
Dadface
- 2,489
- 105
I agree with epenguin who has given you very good advice. If you do need to refer to a formula try to get a good understanding of what the formula is actually referring to. In many cases you will find it's common sense. Without understanding the formula you're just substituting numbers and probably learning very little.