Electricity and Magnetism for JEE Advanced Exam Preparation: Physics

By Aman Goel

JEE Advanced is conducted every by either of the seven Indian Institutes of Technology (IITs) namely IIT Kharagpur, IIT Kanpur, IIT Madras, IIT Delhi, IIT Bombay, IIT Guwahati, and IIT Roorkee or Indian Institute of Science (IISc) Bangalore under the aegis of the Joint Admission Board (JAB).

In the JEE Advanced, questions are asked from three subjects: Physics, Chemistry, and Mathematics. The 12th standard Physics mainly consists of three parts - Electricity and Magnetism, Optics, and Modern Physics. Now, Modern Physics has relatively lesser weightage as compared to the other two. So, it is clear that the paper has more questions from Electricity and Magnetism and hence this topic will be a deciding factor in your overall performance in the paper. In this article, I will walk you through the topics of Electricity and Magnetism and give you some tips on how to prepare for it.

Generally, at coaching/in books (if you are self -studying), you will first study Electricity and then Magnetism. The reason behind that is both topics are quite similar. Their concepts and general formula are almost same for most of the cases. But Electricity is considered to be a bit difficult than Magnetism. So when you master the topic of Electricity, you will easily cruise through Magnetism.

Download JEE Advanced Sample Papers here

Electricity

There are two parts to this:

Electrostatics: This topic is of moderate difficulty. Very good practice of integration and a little memorization will be sufficient for its preparation.

• The first thing that you will learn in Electrostatics is a basic law named as Coulomb’s law. The law describes the concept of force between two charged particles. Generally, questions will not come directly from this topic. Try to solve the questions based on the concept of continuous charge distribution. These are extremely difficult questions and once you understand them, then there’s nothing much to do.
• Next, you will study about Electric field, potential, and potential energy. Mathematically, for solving the problems of this topic, the steps are similar to the topic mentioned above (Coulomb’s law). There are some standard shapes (like line, circle) whose value of field and potential at the general point should be remembered, as these results are directly used in some questions.
• Then comes a small topic called Dipole. The concept is easy, just remember some formulas of field and potential at a general point for small dipole and you can solve almost any question.
• After that, you will study about Electric flux and an important concept known as Gauss’s Law. This is again a fairly easy topic. There are not many variations possible, so solve a few standard problems of it and you will get the idea. 
• The last topic is Capacitance. This is the only topic of electrostatics where you have to study with extreme caution. There are lots of formulas regarding force, field, and energy, also with and without dielectric. You should derive all the formulas by yourself. This will give you a better understanding and logic behind the formulas and help you in memorizing them. In a worst-case scenario, where you don’t remember the formula, you can easily derive it by sacrificing little of your time.

Electrodynamics:  This topic can be considered as a tough topic. And since its weightage in the JEE Advanced is very high, it can also be regarded as an important topic. So you must have a good command over it. For this, apart from good practice of calculus and sharp memory, you have to understand its logic and concepts very clearly. Only after that, you will be able to tackle the problems of this topic.

• The first topic is Ohm’s Law. Here you will get the idea of current, resistance and voltage. You will also know about drift velocity and other properties of electrons that affect current. Questions will not come directly from this topic but nonetheless, you should have an idea about it.
• Then you will learn about the circuits, in which there are different types of arrangements of resistances like series, parallel, or combination of both. To solve these circuits, you need to study about Kirchhoff's Current Law and Voltage Law. Almost every year, a couple of questions comes from this topic alone. You should do a lot of practice on different types of circuits. Try to solve as many complicated questions based on circuits as possible. There are also some special types of circuits like Wheatstone Bridge. Read about them and understand them properly. Initially, you may have some difficulty, so don’t lose your calm and work hard for it.

Magnetism

This phenomenon is also a part of electrodynamics. Again, knowledge of calculus, sharp memory and understanding of Fleming’s Left Hand and Right-Hand rule are the main things you required to solve its problems.

• The first topic which you will study in magnetism is Biot- Savart's Law. This topic will give you the relation between magnetic field and current. Generally, students make a fault in the directions, so take care of that. The only way to make the questions tough is by making the structures formed by the current carrying wire complicated. So practice for as different structures as possible.
• Similar to Gauss’s law, in magnetism, we have Ampere’s law. This law can be used to find magnetic field very easily in some cases. There are very few variations in its problems. Solve some standard questions related to this law, that will be enough.
• The next topic is Electromagnetic Induction. It consists of some basic laws which are Faraday’s law and Lenz’s law. It's very easy to understand them. Sometimes questions directly come from this topic, so make sure you have a very strong command over it.
• Then, you will learn about Inductance. You just need to remember a couple of formulas to prepare for it.
• Finally, you will learn about circuits comprising of RC, LC, and LR. These circuits can be a bit tricky, so good amount of practice is needed.

Some relevant books and materials

• If you are studying any concepts regarding JEE for the first time, H.C.Verma is one of the best books you can get. Solve all of its questions and examples.
• You can also refer books of Arihant Publication for this topic. It will be a good source of problems for practice.
• Last years’ JEE papers are the most important source of questions, especially in Physics. Solve each question completely. It will give you confidence and will help you understand the level of your preparation.

Some final tips

• Electricity and Magnetism is one of the most interesting topics in Physics. After learning this topic, you will be to explain a lot of phenomena that happen in real life. Don’t just study it to get marks in JEE Main or JEE Advanced. Study it to gain knowledge. You can also read different articles about it on the internet.
• You may have thought that there is just too much to memorize. But believe me, you don’t need to have a high memorizing capacity to remember these formulas. Just practice a lot, you will automatically remember the formulas.
• Just enjoy the topic, keep your calm, and work hard, and I am sure you will do quite well in the exam.

About the Author:

Aman Goel is co-founder at a Tech Start-up. He holds a BTech in Computer Science Engineering from IIT Bombay with a JEE Advanced AIR 33 (Year 2013).

During his free time, he enjoys writing articles/blogs. He is an Entrepreneur, Coder, Speed-cuber, gamer, and fan of Air crash investigation!

Read more:

• Thermodynamics for JEE Advanced Exam Preparation: Physics
• Trigonometry for JEE Advanced Exam Preparation: Mathematics
• Calculus for JEE Advanced Exam Preparation
• Analytical Geometry for JEE Advanced Exam Preparation
• Best Books for JEE Advanced Chemistry: A Comparison
• Algebra for JEE Advanced Exam Preparation
• Best books for JEE Advanced Physics: A Comparison
• Best books for JEE Advanced Mathematics: A comparison
• Most scoring topics in JEE Physics
• Most scoring topics in JEE Mathematics
• Most scoring topics in JEE Chemistry
• How To Handle Tough Topics in JEE Physics
• How To Handle Tough Topics in JEE Mathematics
• How To Handle Tough Topics in JEE Chemistry