When a charge moves with an uniform velocity, it creates magnetic field along with electric field. But, velocity is itself relative. So, can we say that magnetic field is a relative quantity ? I mean if a charge is moving with a speed of 20 m/s towards east (w.r.t. ground) and I am moving with the same speed of 20 m/s towards east (w.r.t. ground), then in my reference the charge is stationary (it has 0 velocity). So, will it be producing magnetic field ? If the answer is yes, then why ?
Most of the answers I got say that, 'the object is actually moving'. But, there is no point in saying that an object is "actually moving". If an object has some velocity, it has to be with respect to some observer or something. Velocity is a relative quantity.
Answers
Explanation:
The force on a charged particle due to an electric field is directed parallel to the electric field vector in the case of a positive charge, and anti-parallel in the case of a negative charge. It does not depend on the velocity of the particle.
In contrast, the magnetic force on a charge particle is orthogonal to the magnetic field vector, and depends on the velocity of the particle. The right hand rule can be used to determine the direction of the force.
An electric field may do work on a charged particle, while a magnetic field does no work.
The Lorentz force is the combination of the electric and magnetic force, which are often considered together for practical applications.
Electric field lines are generated on positive charges and terminate on negative ones. The field lines of an isolated charge are directly radially outward. The electric field is tangent to these lines.
Magnetic field lines, in the case of a magnet, are generated at the north pole and terminate on a south pole. Magnetic poles do not exist in isolation. Like in the case of electric field lines, the magnetic field is tangent to the field lines. Charged particles will spiral around these field lines.