N I a 2 0 If the coil consists on N turns, then . B a 3 2) 2 2 2 Magnetic field at the centre: For the field at the centre of the loop,r= 0. Therefore I 2 a Q. 2. Ans. State law connecting the line integral of over a closed path to the net current crossing the B ampere’s circuital area bounded by the path. Use the law to derive the formula for the magnetic field due to an infinitely long straight current carrying wire. circuital law: This law states that the line integral of the magnetic fieldBaround any closed Ampere’s circuit is equal to (permeability constant) times the total current threading or passing through this I closed circuit. Mathematically I B.dI Application of law to an infinitely long straight conductor: Ampere’s Figure shows a circular loop of radius around an infinitely long straight wire carrying a current r I. As the field lines are circular, the field at any point of the circular loop is directed B along the tangent to the circle at that point. By symmetry, the magnitude of field is same at every point B of the circular loop. Therefore, dl cos B.dl r Form law, Ampere’s circuital B 3. A long solenoid with closely wound turns has turns per unit of its length. A steady current flow n I through this solenoid. Use law to obtain an expression for the magnetic field at a Ampere’s circuital
If the coil consists on N turns, then B 0 N I a 2 . 2 a 2) 3 2 2 Magnetic field at the centre: For the field at the centre of the loop,r= 0. Therefore I 2 a Q. 2. Ans. State ampere’s circuital law connecting the line integral of B over a closed path to the net current crossing the area bounded by the path. Use the law to derive the formula for the magnetic field due to an infinitely long straight current carrying wire. Ampere’s circuital law: This law states that the line integral of the magnetic fieldBaround any closed circuit is equal to (permeability constant) times the total current I threading or passing through this closed circuit. Mathematically I B.dI Application of Ampere’s law to an infinitely long straight conductor: Figure shows a circular loop of radius r around an infinitely long straight wire carrying a current I. As the field lines are circular, the field B at any point of the circular loop is directed along the tangent to the circle at that point. By symmetry, the magnitude of field B is same at every point of the circular loop. Therefore, dl cos r Form Ampere’s circuital law, B 3. A long solenoid with closely wound turns has n turns per unit of its length. A steady current I flow through this solenoid. Use Ampere’s circuital law to obtain an expression for the magnetic field at a B.dl