Could you tell me the topics for physics which are quite easy and it's sure question will be their in mains .

Mechanics alone covers around a fifth (or more) of the paper. This has been the usual trend in the past in almost all the competitive examinations and so, it becomes important to master mechanics.

•  Kinematics: The most important concept in Kinematics is the concept of projectile motion along an inclined plane. The concept is a bit tricky and a lot of students face difficulty in understanding it. To score well in exams, make sure you understand it properly. The basic idea is to resolve all the vectors in 2 directions – along the inclined plane and perpendicular to inclined plane.

•  Laws of Motion: A large number of problems are asked from constrained body motion. These questions test the very basic understanding. Rule of thumb for such questions – the length of rope remains constant and so, you can use this fact to come up with the constraint equation.

•  Work, Power and Energy: The law of conservation of mechanical energy and the work energy theorem are 2 most important tools for solving problems. A large number of questions are asked which will require direct application of the work energy theorem. Quite a few theoretical questions are also asked from this chapter, which are meant to check your conceptual understanding.

•  System of Particles: The law of conservation of momentum is one of the most important laws of physics and must be understood well. The students are expected to not only apply the law to a wide variety of situations, but also they are expected to identify the scenarios when the law isn’t applicable.

•  Gravitation: Direct questions are asked from this chapter. A firm command over standard formulae mentioned in JEE syllabus will surely help you to excel in this chapter.

•  Rotational Mechanics: This is the lesson where most of the students face difficulties as this topic is quite diverse. Questions from this chapter often involve concepts from previous chapters. For instance, a collision problem might require you to apply the law of conservation of linear momentum as well as angular momentum. Questions of pure rolling often require a good knowledge of frictional force taught in Laws of motion.

•  Simple Harmonic Motion: This chapter involves good amount of mathematics. Students are expected to know how to calculate time period of a simple harmonic motion and they should know both force/torque method and energy method to compute the time period of SHM.

•  Elasticity: It’s a simple chapter, where most questions are straight forward – application of formula based.

•  Fluid Mechanics: The topic of surface tension attracts the most number of questions. Students should be aware of the property of fluid’s surface to behave as a stretched membrane.

•  Waves and Sounds: This chapter involves a lot of standard formulae and so, it should be studied well. Most of the questions are from Doppler’s effect and so, ample of practice is needed.