Here are the important topics given below to study for Physics, Chemistry, Mathematics.

JEE Main Important Topics for Physics

    Magnetics-One of the topic from which maximum questions are asked in the question paper.

    Modern Physics-It is one of the important and scoring topics for both JEE Main and JEE Advanced. Also, candidates must check sub-topics such as radioactive decay of substances, nuclear fission and fusion, dual nature of matter and X-rays in detail.

    Optics-It is a relatively easy topic to study.

    Oscillation and Waves-Must study this topic in detail.

    Electromagnetic Induction and AC- Generally, numerical problems are asked from this topic.

    Current Electricity- Another important topic which candidates need to cover. Ohm’s law, colour code for resistors etc are asked from this.

    Electrostatics- According to the previous year trend, this is the most scoring topic as almost four questions are asked from it every year in.

 

JEE Main Important Topics for Chemistry

    Organic Chemistry- Purification and Characterisation of Organic Compounds, Some Basic Principles of Organic Chemistry, Hydrocarbons,Organic Compounds Containing Oxygen, Organic Compounds Containing Nitrogen, Bio Molecules etc.

    Inorganic Chemistry- Classification of Elements and Periodicity in Properties, General Principles and Process of Isolation of Metals, Hydrogen, s - Block Elements (Alkali and Alkaline Earth Metals), Co-ordination Compounds, Environmental Chemistry to name few.

    Physical Chemistry- Some Basic concepts in Chemistry,States of Matter, Atomic Structure, Chemical Bonding and Molecular Structure,Chemical Thermodynamics, Equilibrium, Surface Chemistry,Chemical Kinetics and Redox Reactions and Electrochemistry.

 

JEE Main Important Topics for Mathematics

    Permutations & Combinations

    Definite Integration

    Quadratic Equation

    Conic Section

    Differential Equation

    Probability

    Determinants

    Application of Derivatives

    Vector & 3D Geometry

    Complex Numbers

    Coordinate Geometry; Matrices in Algebra: Circle, Parabola, Hyperbola in Coordinate Geometry

    Functions, limits, Continuity & Differentiability

    Sequences engineers

    Calculus; Definite Integral in Calculus

You can also refer the below given article for the further detail.

https://engineering.careers360.com/articles/jee-main-2019

Good Luck!