why a solenoid tends to constract when a current is passed through it?

A long solenoid has 500 turns. When a current of 2 A is passed through it, the resulting magnetic flux linked with each turn of the solenoid is 4 xx 10^(-3)Wb. The self-inductance of the solenoid is

Free electron always keep on moving in a conductor. Even then, no magnetic force acts on them in a magnetic field unless a current is passed through it. Why?

What happens when CO_2 is passed through lime water?

What happens when: SO_3 is passed through water?

A rubber band is covered with a conducting and current passed through it in the direction as shown in the figure. What happens, when it is placed in the magnetic field vecB shown in the figure

A rubber band is covered with a conducting and current passed through it in the direction as shown in the figure. What happens, if the current is reversed in the rubber band

What happens when a strong current is passed through a semiconductor? Explain.

An iron rod of volume 10^-4m^3 and relative permeability 1000 is placed inside a long solenoid wound with 5 turns/cm. If a current of 0.5A is passed through the solenoid, find the magnetic moment of the rod.