Physics
Moving Charges and Magnetism
गतिमान आवेश और चुंबकत्व
In this Class 12 Physics chapter, students explore how moving electric charges and currents produce magnetic fields and how magnetic fields affect charged particles and current-carrying conductors. The chapter develops the Biot–Savart law, Ampere’s circuital law, the Lorentz force, motion of charged particles in magnetic fields, and the force and torque on current loops. It also introduces the moving-coil galvanometer and connects these ideas to the measurement and control of electric current.
1Magnetic Force and Magnetic Field
चुंबकीय बल और चुंबकीय क्षेत्र
In this Class 12 Physics topic from Moving Charges and Magnetism, students learn how magnetic fields are produced by moving charges and electric currents and how these fields exert force on charged particles and current-carrying conductors. The topic develops the Lorentz force concept, Fleming’s left-hand rule, right-hand rules for field direction, and the motion of charged particles in magnetic fields. Students also interpret field lines and apply these ideas to solve numerical and conceptual problems.
0 questionsMotion in a Magnetic Field
चुंबकीय क्षेत्र में आवेशित कण की गति
In this Class 12 Physics topic from the chapter Moving Charges and Magnetism, students learn how a magnetic field affects a moving charged particle through the Lorentz force. The topic explains why a particle may follow circular, helical, or straight-line motion depending on the direction of its velocity relative to the field. Students also study the roles of magnetic field strength, charge, mass, velocity, radius, time period, and cyclotron frequency, and apply these ideas to numerical problems and practical devices such as the cyclotron.
0 questionsMagnetic Field due to a Current Element (Biot-Savart Law)
धारा तत्व के कारण चुंबकीय क्षेत्र (बायो–सावर्ट नियम)
In this Class 12 Physics topic from “Moving Charges and Magnetism,” students learn how a small current element produces a magnetic field and how the Biot–Savart law relates its magnitude and direction to the current, element length, distance, and angle. The topic develops the vector form of the law, the right-hand rule, and superposition, then shows how integration is used to find fields for common current-carrying conductors such as a straight wire or circular loop. It also builds the foundation for interpreting magnetic effects of steady currents.
0 questionsMagnetic Field on the Axis of a Circular Current Loop
वृत्ताकार धारा-लूप की अक्ष पर चुंबकीय क्षेत्र
In this Class 12 Physics topic from Moving Charges and Magnetism, students learn how to determine the magnetic field produced by a circular current loop at a point on its axis. The topic applies the Biot–Savart law and the principle of superposition to derive the field expression, explains its direction using the right-hand rule, and examines how the field varies with current, loop radius, and distance from the centre. Special cases such as the field at the centre and at large distances help connect the formula with physical interpretation.
0 questionsAmpere's Circuital Law
एम्पियर का परिपथीय नियम
In this Class 12 Physics topic from Moving Charges and Magnetism, students learn how Ampere’s Circuital Law relates the circulation of the magnetic field around a closed path to the net current enclosed by that path. The topic develops the line-integral form of the law, explains the role of symmetry in choosing an Amperian loop, and applies the principle to find magnetic fields around long straight conductors, solenoids, and toroids. It also strengthens understanding of current, magnetic field, and field-line behavior.
0 questionsThe Solenoid and the Toroid
सोलनॉइड और टोरोइड
In this Class 12 Physics topic from Moving Charges and Magnetism, students learn how a current-carrying solenoid produces a nearly uniform magnetic field inside its turns and a weaker field outside. They study how the field depends on current, number of turns, and the medium, and use Ampere’s circuital law to understand the result. The topic also explains the magnetic field of a toroid, its circular arrangement of turns, and the confinement of the field within its core.
0 questionsForce between Two Parallel Currents (the Ampere)
दो समानांतर धारावाही तारों के बीच बल (ऐम्पियर)
In this Class 12 Physics topic from Moving Charges and Magnetism, students learn how two long, parallel current-carrying conductors exert magnetic force on each other. They understand why currents in the same direction attract while opposite currents repel, and use the relation F/L = μ₀I₁I₂/(2πd) to calculate force per unit length in vacuum. The topic also connects this result with the classical force-based definition of the ampere and strengthens understanding of magnetic fields produced by electric currents.
0 questionsTorque on Current Loop, Magnetic Dipole
धारा-लूप पर बलाघूर्ण और चुंबकीय द्विध्रुव
In Class 12 Physics, this topic from Moving Charges and Magnetism explains how a magnetic field acts on a current-carrying loop. Students learn to calculate the torque on the loop, understand its dependence on current, area, number of turns, and the angle with the field, and represent the loop as a magnetic dipole with magnetic moment m = NIA. The topic also connects torque with stable and unstable orientations and the potential energy of a magnetic dipole in an external field.
2 questionsThe Moving Coil Galvanometer
चल-कुंडली गैल्वेनोमीटर
In Class 12 Physics, the topic The Moving Coil Galvanometer introduces the working principle of a sensitive instrument used to detect and measure small electric currents. As part of Moving Charges and Magnetism, students study the force and torque on a current-carrying coil in a magnetic field, the role of the radial field, and how deflection relates to current. They also learn current sensitivity, factors affecting accuracy, and the conversion of a galvanometer into an ammeter or voltmeter.
0 questions