Biot-Savart law, field of circular loop
- A tightly wound 100 turns coil of radius 10 cm carries a current of 7 A. The magnitude of the magnetic field at the centre of the coil is (Take permeability of free space as 4π×10^-7 SI units): Answer: 4. 4.4 mT Key idea: Field at the centre of a circular coil of N turns: B=μ₀NI/2R . B=frac4π×10⁻⁷×100×72×0.1=frac8.8×10⁻⁴0.2≈4.4×10⁻³... 1
- A very long conducting wire is bent in a semi-circular shape from A to B as shown in figure. The magnetic field at point P for steady current configuration is given by : Answer: 4. μ₀ i/4R[1-2/π] pointed away from page Add the fields of the three parts at P: two semi-infinite straight wires and one semicircle... 1
- Given below are two statements :Statement I : Biot-Savart's law gives us the expression for the magnetic field strength of an infinitesimal current element (Idl) of a current carrying conductor only.Statement II : Biot-Savart's law is analogous to Co… Answer: 4. Statement I is correct and Statement II is incorrect Statement I: Biot-Savart law gives the field due to a small current element... 1
- A long wire carrying a steady current is bent into a circular loop of one turn. The magnetic field at the centre of the loop is B. It is then bent into a circular coil of n turns. The magnetic field at the centre of this coil of n turns will be Answer: 1. n²B Field at the centre of a circular coil: B=μ₀ N I/2r . One turn: wire length L=2π r , so B=μ₀ I/2r . n turns from the same wir... 1