Why is the magnetic field radial?
(A) To make field stronger. (B) To make field weaker. Hint: The magnetic field is made radial in a galvanometer to concentrate the field in a circular region uniformly in all directions and hence, make it linear in angular direction. …
How is radial magnetic field achieved?
Solution : Radial magnetic field is that field, in which the plane of the coil in all positions is parallel to the direction of the magnetic field. A radial magnetic field has been achieved by (i) properly cutting the magnetic pole pieces in the shape of concave faces. (ii) using a soft iron core within the coil.
What is radial electric field?
Given a point charge, or a particle of infinitesimal size that contains a certain charge, electric field lines emanate radially in all directions. If the charge is positive, field lines point radially away from it; if the charge is negative, field lines point radially towards it.
What is the importance of radial magnetic field and how is it produced?
(a) Importance and production of radial magnetic field : In a radial magnetic field, magnetic torque remains maximum for all positions of the coils. It is produced due to cylindrical pole pieces and soft iron core.
What is the function of uniform radial field?
The Uniform Radial Magnetic Field keeps the plane of coil always parallel to direction of the magnetic field. The soft iron core attracts the magnetic lines of force and hence the strength of the magnetic field increases if we use soft iron core. Thus the sensitivity of galvanometer increases.
Why it is an advantage for the armature to rotate in a radial magnetic field rather than a uniform one?
b. Explain why it is advantage for armature to rotate in radial magnetic field rather than a uniform one. The back emf is zero when the armature is at rest. The magnitude of back emf increases with increasing the speed of armature which ultimately increasing the eddy currents.
Can moving coil galvanometer measure AC?
A moving coil galvanometer cannot be used to detect a.c. in a circuit, since it measures the average value of current and the average value of a.c. over a complete cycle is zero.
Why a coil is wrapped on a conducting frame in a galvanometer?
The coil of a galvanometer is wound on a metal frame so that it provide electromagnetic damping due to production of eddy currents in the frame which oppose the motion of the coil.
Why do we use soft iron core in moving coil galvanometer?
A soft iron core is used in galvanometer because the magnetic lines of force can be attracted by the soft iron core. This attraction of magnetic lines of force increases the magnetic field which increases the sensitivity of galvanometer.
Why is soft iron core used in the coil?
A soft iron core is used in a moving coil galvanometer. The soft iron core attracts the magnetic lines of force and hence the strength of the magnetic field increases if we use soft iron core. Thus the sensitivity of galvanometer increases.
Why is soft iron used on a moving arm?
Iron is said to be magnetically soft, it can be very easily magnetized, even in a weak field. Hence, in moving coil galvanometer, to increase the strength of magnetic field a soft iron core is used since, soft iron allows passage of magnetic lines of force.
Can soft iron be easily magnetized?
Soft Iron Base Alloys Soft magnetic alloys are ferromagnetic materials that are easily magnetized and de-magnetized. They rely on various additions of phosphorus, nickel, and silicon to optimize magnetic induction, permeability, and coercive force.
Where is soft iron used?
Soft iron. “Soft” (annealed) iron is used in magnetic assemblies, direct current (DC) electromagnets and in some electric motors; and it can create a concentrated field that is as much as 50,000 times more intense than an air core.