1) An electric current through a metallic conductor produces a  concentric circlescurrentdecreaseselectromagnetfield linesincreasesmagnetic fieldmagnetic polesmagnetisenparallelrightright-hand thumbsoftsolenoiduniform around it.
2) The magnitude of the magnetic field produced at a given point  concentric circlescurrentdecreaseselectromagnetfield linesincreasesmagnetic fieldmagnetic polesmagnetisenparallelrightright-hand thumbsoftsolenoiduniform as the current through the wire increases.
3) The magnetic field produced by a given current in the conductor  concentric circlescurrentdecreaseselectromagnetfield linesincreasesmagnetic fieldmagnetic polesmagnetisenparallelrightright-hand thumbsoftsolenoiduniform as the distance from it increases.
4) The field lines of a magnetic field around a straight conducting wire is represented by a pattern of  concentric circlescurrentdecreaseselectromagnetfield linesincreasesmagnetic fieldmagnetic polesmagnetisenparallelrightright-hand thumbsoftsolenoiduniform around the wire. These become larger and larger as distance from wire  concentric circlescurrentdecreaseselectromagnetfield linesincreasesmagnetic fieldmagnetic polesmagnetisenparallelrightright-hand thumbsoftsolenoiduniform.
5) If you are holding a current-carrying straight conductor in your  concentric circlescurrentdecreaseselectromagnetfield linesincreasesmagnetic fieldmagnetic polesmagnetisenparallelrightright-hand thumbsoftsolenoiduniform hand such that the thumb points towards the direction of  concentric circlescurrentdecreaseselectromagnetfield linesincreasesmagnetic fieldmagnetic polesmagnetisenparallelrightright-hand thumbsoftsolenoiduniform and your fingers will wrap around the conductor in the direction of the  concentric circlescurrentdecreaseselectromagnetfield linesincreasesmagnetic fieldmagnetic polesmagnetisenparallelrightright-hand thumbsoftsolenoiduniform of the magnetic field.This is known as the  concentric circlescurrentdecreaseselectromagnetfield linesincreasesmagnetic fieldmagnetic polesmagnetisenparallelrightright-hand thumbsoftsolenoiduniform rule.
6) If there is a circular coil having n turns, the field produced is  concentric circlescurrentdecreaseselectromagnetfield linesincreasesmagnetic fieldmagnetic polesmagnetisenparallelrightright-hand thumbsoftsolenoiduniform times as large as that produced by a single turn.
7) A coil of many circular turns of insulated copper wire wrapped closely in the shape of a cylinder is called a  concentric circlescurrentdecreaseselectromagnetfield linesincreasesmagnetic fieldmagnetic polesmagnetisenparallelrightright-hand thumbsoftsolenoiduniform.The ends of  concentric circlescurrentdecreaseselectromagnetfield linesincreasesmagnetic fieldmagnetic polesmagnetisenparallelrightright-hand thumbsoftsolenoiduniform behave as  concentric circlescurrentdecreaseselectromagnetfield linesincreasesmagnetic fieldmagnetic polesmagnetisenparallelrightright-hand thumbsoftsolenoiduniform.
8) The field lines inside the solenoid are in the form of  concentric circlescurrentdecreaseselectromagnetfield linesincreasesmagnetic fieldmagnetic polesmagnetisenparallelrightright-hand thumbsoftsolenoiduniform straight lines.
9) The field is  concentric circlescurrentdecreaseselectromagnetfield linesincreasesmagnetic fieldmagnetic polesmagnetisenparallelrightright-hand thumbsoftsolenoiduniform inside the solenoid.
10) A strong magnetic field produced inside a solenoid can be used to  concentric circlescurrentdecreaseselectromagnetfield linesincreasesmagnetic fieldmagnetic polesmagnetisenparallelrightright-hand thumbsoftsolenoiduniform a piece of magnetic material, like  concentric circlescurrentdecreaseselectromagnetfield linesincreasesmagnetic fieldmagnetic polesmagnetisenparallelrightright-hand thumbsoftsolenoiduniform iron, when placed inside the coil. The magnet so formed is called an  concentric circlescurrentdecreaseselectromagnetfield linesincreasesmagnetic fieldmagnetic polesmagnetisenparallelrightright-hand thumbsoftsolenoiduniform.