Before You Begin
Question #42787
The Question
An infinite mechanical ladder network is constructed using massless springs, analogous to an infinite capacitor ladder. The network consists of nodes numbered . For each , a series spring of stiffness connects node to node , and a shunt spring of stiffness connects node to a fixed rigid wall. A constant static force is applied at node 0, and the system is allowed to reach static equilibrium. Let be the elastic potential energy stored in the first series spring (between node 0 and node 1), and be the total elastic potential energy stored in all the shunt springs combined. What is the ratio ?
Options
- A.
- B.
- C.
- D.
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Multi-Concept_Bridge
Master problems that require linking physics and math concepts to solve complex competitive questions.
Concepts Behind This Question
Infinite Series Capacitance|Effective Spring Constant|Energy Partitioning
Why This Question Is Tricky
Common Mistakes
This question tests the student's ability to map an infinite capacitor ladder to a mechanical spring system and correctly evaluate the spatial distribution of potential energy.
A common trap (Energy Equipartition Logic) is assuming that the total energy is equally partitioned between the series and shunt components (), which leads to the incorrect ratio of 2/3.
Another trap is ignoring the infinite series and only comparing the first stage energies, leading to 3/2.
Students must recognize that force (analogous to charge) attenuates geometrically across the nodes, requiring an infinite geometric sum of the energy density to find the true total shunt energy.
Quick Facts About This Question
Question Information
| Subject | Physics |
| Chapter | Electrostatic Potential and Capacitance - Class 12 |
| Concept | Infinite Series Capacitance |
| Difficulty | 8 |
| Cognitive Load | 7 |
| Target Solve Time | 160 sec |
| Access | Free |