# class 12 ## West Bengal Board Question Paper | class 12 (Commerce)

Accountancy 2015 2016 2017 2018 2019 2022 Business Studies 2015 2016 2017 2018 2019 2020 2022 Costing and Taxation 2014 2015 2016 2017 2018 2019 2022 Commercial Law and Preliminaries of Auditing 2015 2016 2017 2018 2019 2022 Home Management and Family Resource Management 2015 2016 2017 2019 Economics 2015 2016 2017 2018 2019 2022

## Magnetc field due to toroid using Ampere’s circuital Law

A toroid is an endless ring shaped solenoid.Consider a toroid having n turns per unit length through which current i is flowing [ figure given below]. Magnetic field is set up inside the turns of the toroid. The magnetic lines of force inside the toroid are concentric circles. From symmetry, the magnetic field at all …

## Magnetic Field due to a Straiight Solenoid using Ampere’s Circuital Law

A solenoid consists of an insulated long wire closely wound in the form of a helix, whose length is very long in comparison to its diameter. Let us consider a long straight solenoid having n turns per unit length and carrying current i. The magnetic field in the solenoid when current passes through it is …

## Magnetic Field due to infinite long carrying current straight wire using Ampere’s Circuital Law

Consider a circular wire of radius a and of infinite length. A steady current I is flowing through it. A magnetic field is produced around it due to flowing current. The magnetic field lines are concentric circles with their centres on the axis of the wire [Figure given below]. Case I. Magnetic field intensity at …

## Ampere’s Circuitial Law

Ampere circuital law states that the line integral of magnetic field around any closed path in vacuum is equal to absolute permeability times the total current enclosed by the path.Mathematically, where is the magnetic field, is the small element, is the absolute permeability of vacuum and I is the current. denotes integral around closed path. …

## Magnetic field due to a current carrying circular loop

Let us consider a circular coil of radius a with centre O and the plane of the coil is perpendicular to the plane of the paper [Fig. 3.1.13]. Current i flows through the coil in the direction as shown in the figure. Let P be a point on the axis of the circular coil at …