Ahh, concentration. The great myth about concentration is that it is something that we do actively. When I was a kid and people told me to "Concentrate!" I felt that I had to do something, like, strain my muscles a little, wrinkle my face and look "concentrated". Of course this can't be farther from the truth. Concentration is a mental state. In western culture it is considered difficult to control mental states, so mastering concentration is considered "hard".
In fact, the value of the concentration state is to be able to keep attention fixed on one object, event, thought or person for prolonged amount of time.
So the problem has two parts - to be able to control attention at all and after that to keep it fixed on something longer than a few seconds.
Controlling attention is a huge topic, I won't go into it now. Keeping attention fixed on something is a popular goal in PD. Lots of people spend a lot of time and effort trying to "learn" it. I find it a little bit amusing, because these people usually can have their attention fixed for hours with great ease.
TV, reading, watching a movie, long commute... in all these and many other situations our attention becomes fixed on something and stays there without any effort from our side. Yes, you can say, that these are wrong and unproductive contexts. People often dismiss the skills they have just because these skills are demonstrated in the "wrong" contexts. Well, we the bosses, we can take the skill out of one context and use it in the other.
The key to the fixed attention is being in the certain state. In a trance state. That is why meditation helps concentration - after the months of training it teaches you to get in a trance state. Of course, driving a car has the very same effect.
So to get into the state of fixed attention is not a problem. The problem is to stay in that state throughout the disturbances. It is hard. For example any sudden and loud noise will attract the attention of the most people. I guess with practice one can learn how to avoid this reaction, but I find that earplugs are a better solution.
Similarly with the other environmental factors - if it is too hot, too cold, too noisy, too many visual distractions it is easier to get rid of all this, than to learn how to ignore it.
Answering the original question, about studying...
Aditya, please note that any prolonged mental work requires some lead-in time. Usually it is estimated as 15 minutes after the last serious interruption.
Serious, means, that your attention has fully switched to another process, not the momentary lapse needed to answer a trivial question. So it is ok to let your mind wonder during this lead-in process. After that you have a good chance to enter the flow state of high productivity. It is a form of trance, where the time distorts and you acquire the resistance to external disturbances. But if the problem is too hard for your current skill level, you might never enter this state, concentration or, not. If this is the case, make a step back, review the previous material, consult someone, to make the task easier.
You can work on your concentration skills if you want, but don't expect it to be the miracle solution to your studying problems
Also you can use reading as a form of meditation. Read for a while untill you are at the zone and then, carefully switch to your studies, while maintaining the mental state. It can help.