Moving Charges and Magnetism

Absolutely, if thoroughly practiced and understood, these solutions are more than enough to help one score full marks in this chapter. It comprises all key concepts such as laws, derivations, and applications and covers all questions from the NCERT textbook. The step-by-step solutions help students understand the core logic of solving the questions and structure the answers as like by the CBSE examiners. For those who want to score high in board exams, they need consistent practice of these solutions to be familiar with the question pattern, especially derivation-based and long-answer questions.

The principle that a current-carrying coil placed in a magnetic field feels a torque is behind a moving coil galvanometer. The coil rotates due to this torque, and the angle of deflection is proportional to the current. For the conversion of a galvanometer into an ammeter, a high current is allowed to bypass the Galvanometer by connecting a low resistance (shunt) in parallel. A high resistance is connected in series to restrict current and convert it into a voltmeter. The conversions make the galvanometer ideal for measuring higher ranges of voltage and current in practical circuits.

This force is exerted by the magnetic fields produced by the parallel current-carrying conductors. If the currents run in the opposite directions, they repel and if they run in the same direction, then they attract. The force is exerted because each conductor lies in the magnetic field produced by the other. A force acts on the moving charges in each wire, according to the Lorentz force law. This concept is fundamental in understanding electromagnetic interactions in power transmission lines and circuits. It is not just theoretical, it defines the SI unit of current and the ampere.

When electric current passes through a long coil of wire, it generates a nearly uniform magnetic field inside it, it is the solenoid. Outside this solenoid, the magnetic field is weak and negligible. On the other hand, in a toroid, the magnetic field is completely confined within its core, which forms a closed loop. It is a solenoid bent into a circular shape (doughnut-shaped). Outside the toroid, there is essentially no magnetic field. By understanding this difference, the students can design electromagnetic devices more effectively. The toroids are useful in lowering electromagnetic interference.