A gas has to become ionisied in order to become a conductor. It must have a chain reaction in which atoms in it became unstable, in which they loose stabile electronic configuration. In order for a gas to become a conductor, it must have free particles, and it can happen only in ionisied gas.
Explanation:
(a) We have,
Length of solenoid, l = 55 cm = 0.55 m
Diameter of the solenoid, d = 10 cm
Radius, r = 5 cm = 0.05 m
Number of loops in the solenoid is 1000.
(a) The self inductance in the solenoid is given by :

A is area

(b) The energy stored in the inductor is given by :

Hence, this is the required solution.
Answer:
Magnetic field is the strength of magnetism created by a magnet, whereas the magnetic force is the force due to two magnetic objects. The concepts of magnetic field and magnetic force are widely used in fields such as classical mechanics, electromagnetic theory, field theory and various other applications.
Explanation:
The answer is A. Mountains form because tectonic plates overlap. Earthquakes form because of the moving of tectonic plates. The moving of tectonic plates causes holes in the crust so magma from the mantle escapes and erupts from volcanoes. I hope I helped!