What factors contribute to the deflection of a galvanometer?

[Sukuya]

In a galvanometer the magnetic poles are cut in such a fashion which ensures radial magnetic field. If field is radial then the angle between magnetic moment i.e Area vector of the coil and field is zero. Thus the coil should not experience any torque when current is passed through the coil. Then how come there is deflection.

 

[UltrafastPED]

Does your galvanometer work like this one?

http://www.citycollegiate.com/galvanometer_XIIb.htm

 

[Sukuya]

Yes, like this one. The link says :
"In the space between it and the pole pieces, where the coil moves freely, the soft iron cylinder makes the magnetic field stronger and radial such that into whatever position the coil rotates, the magnetic field is always parallel to its plane."

My doubt is that when field is radial it should be perpendicular to the area of coil rather than parallel to its plane.

 

[UltrafastPED]

Since they do work there must be a problem in your understanding; here is another good source:
http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/galvan.html

 

[pmacias]

The deflection of a galvanometer is not solely based on the angle between the magnetic moment and the radial field. There are other factors at play, such as the strength of the magnetic field and the current passing through the coil. Additionally, the design of the galvanometer may also play a role in the deflection.

In a galvanometer, the coil is suspended within the magnetic field and is able to rotate freely. When a current is passed through the coil, it creates a magnetic field around the coil which interacts with the external magnetic field. This interaction results in a torque being applied to the coil, causing it to rotate and deflect.

Furthermore, the radial field in a galvanometer is not perfectly uniform and may have variations in strength and direction. This can also contribute to the deflection of the coil.

In summary, the deflection of a galvanometer is a complex phenomenon that involves multiple factors, not just the angle between the magnetic moment and the radial field. It is important to consider all these factors when analyzing the behavior of a galvanometer.