Who was the first to observe the magnetic effect of electric current?

Magnetic field inside a long solenoid carrying current is

The magnetic field lines due to a straight wire carrying a current are

Which of the following correctly describes the magnetic field near a long straight wire?

The relative strength of the magnetic field is shown by the degree of closeness of the field lines.

A current carrying conductor is held in exactly vertical direction. In order to produce a clockwise magnetic field around the conductor, the current should be passed in the conductor:

Which of the following diagrams correctly shows the magnetic field produced by a current- carrying wire?

The shape of the magnetic field lines produced by a current carrying conductor are:

The pattern of the magnetic field produced by the straight current carrying conducting wire is

The nature of magnetic field line passing through the centre of current carrying circular loop is :