Hi

Yes, the questions in jee main & jee advanced is from 11th and 12 th lessons as there syllabus is syllabus of 11 & 12th physics, chemistry & maths .

For your reference,

JEE main  syllabus is provided below subject wise :-

.                  PHYSICS

*Physics and measurement

*Kinematics

*Laws of motion

*Gravitation

*Rotational motion

*Thermodynamics

*Work, energy and power

*Properties of solids and liquids

*Oscillations and waves

*Electronic devices

*Kinetic theory of gases

*Current electricity

*Communication systems

*Electromagnetic induction and alternating currents

*Magnetic effects of current and magnetism

*Optics

*Electromagnetic waves

*Atoms and nuclei

*Electrostatics

*Dual nature of matter and radiation

*Experimental Skills

.                  CHEMISTRY:-

Physical chemistry:-

*Some basic concepts in chemistry

*Atomic structure

*Chemical bonding and molecular structure

*States of matter

*Chemical thermodynamics

*Solutions

*Equilibrium

*Redox reactions and electrochemistry

*Chemical kinetics

*Surface chemistry

Organic Chemistry:-

*Some basic principles of organic chemistry

*Purification and characterisation of organic compounds

*Hydrocarbons

*Chemistry in everyday life

*Principles related to practical chemistry

*Organic compounds containing halogens

*Organic compounds containing oxygen

*Organic compounds containing nitrogen

*Polymers

*Biomolecules

Inorganic Chemistry:-

*Classification of elements and periodicity in properties

*Block elements i. e alkali and alkaline earth metals

*Hydrogen

*P Block elements group 13 to group 18 elements

*d- and f - block elements

*Co-ordination compounds

*Environmental chemistry

*General principles and processes of isolation of metals

.                        MATHS

* Sets, relations and functions

*Matrices and determinants

*Complex numbers and quadratic equations

*Mathematical induction

*Permutations and combinations

*Mathematical reasoning

*Limit, continuity and differentiability

Integral calculus

*Three-dimensional geometry

*Differential equations

*Binomial theorem and its simple applications

*Sequence and Series

*Vector algebra

*Statistics and probability

*Trigonometry

*Co-ordinate geometry

You can also refer to our page for jee main syllabus at

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

Coming to jee advanced,

The syllabus of jee advanced is almost the same as that of jee main there's only slight difference in the  syllabus of jee main and advanced. You can get the complete syllabus of JEE advanced by going through the link provided below

https://engineering.careers360.com/articles/jee-advanced-syllabus/amp

These syllabus  will  be  very  helpful  in  your  preparation  because  it  will  let  you know  the  topics  and  chapters which are included  in  your  examination   , so go well  through  your  syllabus  and  plan your  studies  so  that  you  can  score  well in  your  jee .

To prepare well you can go for our jee program at the convenience of your home, the link for the same is provided below

https://learn.careers360.com/knockout-jee

Thank you