General question solving techniques that I used are as follows:
- Remember all the formulas of Physics, Chemistry and Maths well. If you take time to recall the formula, you will lose the time.
- Try to get hint from question and options, which chapter or topic or concept is asked. Because JEE will have questions from almost all chapters of syllabus.
- Try to solve options. (Be careful, it’s a risky way. You may end up answering an easy question in a wrong way.) But, it may be useful at times. (Especially in BITSAT and JEE advanced. I couldn’t use option solving much in JEE main.)
- Think for another method to solve the problem. It may be a shortcut which might be valid only for that particular question (due to some special symmetry). Such tricks will solve your question in 1 minute instead of 4–5 minutes.
One such question (related to point 4) was asked in JEE main 2016. It had a straight line graph between Pressure and volume of a gas. We had to find the maximum temperature of an ideal gas during undergoing this process. The usual method is to find T as f(V) or f(P), then equating derivative of T =0.
Another approach (that I found out during the exam) is to think about PV=constant graphs at different temperature, which will help you realise that the hyperbola shifts “upward” along line P=V as temperature increases.
So, the given PV line will touch the “highest” possible hyperbola at the midpoint of its intersections with x and y axes. Hence, the maximum temperature will occur at the midpoint for the given line. (By chance that line had slope = -1.)