Time and again, it has been propounded by many faculties and past examinees that JEE is a test of our nerves. It’s a journey where one can’t anticipate what happens next, albeit we may plan out certain framework to go about. The Physics syllabus is a glaring testimony to that fact. The general way of conduction of Physics syllabus starts and heavily emphasizes on the Newtonian mechanics and periodic motion in accordance to said mechanics. The distinctive feature of these chapters is the easy real-world visualization that’s possible here, which is by far, one of the most appealing things about these chapters. However, after the comfort of the easily visualizable mechanics, comes Transverse Waves, one in a series of topics, which baffles the mind of a JEE aspirant used to mechanics.
In my experience, ‘Transverse waves’ was a rude shock from the comfort zone of Newtonian mechanics part. The main problem about this topic, in my opinion, was the very abstract behavior in which the chapter is presented to us. Though it’s easily seen that a wave develops when a rope is flicked, the more nuanced aspects of wave mechanics (which is what JEE, be Mains or Advanced, will obviously focus on) are lost in realm of cerebral darkness. To tackle this, here’s a short generic list of points to keep in mind when concerned with this chapter, from my experience about the chapter:
1. Practice SHM problems really well
Let’s face it. Many amongst us, allocate study time to chapters based on their empirical weightage in the exams. Such strategy is not only wrong but also the very basis behind it is redundant. To address the double issue, SHM is a great example. First of all, JEE has NO fixed weightage and they do tend to change it every next year. SHM, even though having less weightage, is one of those chapters which may have lesser weightage in terms of standalone sums, but it’s application in a legion on other topics effectively increases its importance.
And one of those topics is transverse waves. Transverse waves relies on SHM a lot and the initial parts of it are a direct borrowing from that chapter. Thus, SHM could be called as a sort of foundation to transverse waves. In order to do well in transverse waves, a sound background of SHM is essential.
2. Formulae in Transverse Waves
This chapter shall be, most probably, your first brush with a chapter that has potentially a lot of formulae to mug up. Trust me, you have to mug some stuffs up. However, it’s not to say that rote learn the entire chapter. Unlike mechanics, here there isn’t a simple algorithmic ‘F = ma’ way of deriving stuff. In order so that you can solve sums pertaining to transverse waves, it’s much better to learn formulae by heart , say, energy of a travelling and standing waves. They can’t be easily derived on spot, even if you know the process. At the same time, especially for JEE Advanced, it’s imperative to remember how the formula was derived, for questions aren’t as direct in JEE.
3. Travelling Waves v/s Standing Waves
This is a major hunch when it comes to this chapter. Although confusion here is inevitable, it’s best addressed at a very early stage. Most people try to solve this issue from ignoring it or glossing over it. However, a stronger and more comprehensive way of doing this is by comparatives. Keep a sheet or so handy, where you’ve noted the distinctions between these two types of waves, like origin, formulae, trends in energy, etc. By doing so, on a regular basis, there will be absolutely no ground for confusion here. Also, you could try solving a sum of travelling wave, considering it to be a standing one. Such analysis leads to a better understanding of their inherent differences.
4. Ways of solving
Conventional methods of solving problems till now may not work here. That is so because, the calculation here is quite much related to trigonometry and higher and/or fractional powers, something we encounter to a lesser degree in previous mechanics chapters. Thus, time management and knowing standard ways of solving a sum becomes essential. Start speed solving. And this is not just limited to this topic. Take a bunch of moderate level questions. Time yourself and solve them sequentially and in cycles. Take as many cycles as you can.
This is something that will, honestly, not come by mere studying but by pure experience of the topic at hand. Now, we generally view transverse waves as something highly exclusive of Newtonian mechanics. However, JEE exploits these very generalizations. Try and link every part of waves to mechanics. I feel this is the best served by trying different and at times, quirky types of problems like a sum exploiting the fact that waves carry energy (even the ones on ropes) can be used to say, heat water. The possibilities are for you to explore.
Stop viewing transverse waves as being alien to Newtonian mechanics but as an extension to it. Then the problem of visualization will be easily addressed.
Conclusively ,If you keep these things in mind, transverse waves would be a cakewalk. And the fact that transverse waves is the stepping stone to sound waves and wave optics is incentive enough for a JEE aspirant to take serious cognizance of this topic. With that, I’ll bring this to a close, All the Best, may the odds be ever in your favour 🙂