I have a very fundamental question, will an electric bulb glow with one point connected to the positive terminal of the electric line and the other point to earth? In my school some 10 years back I learnt that we are connecting the two points of the bulb to positive and negative to make the connection closed.
As earth is considered as a huge potential of ions it could be considered as the negative side. If my thinking is wrong then why do the LEDs glow in the tester? In the tester we touch the tail which is indirectly connected to earth.
Note I dont know what the tester is called in other countries. The Tester is a small instrument to check if the current flows in a circuit or not and is size of a pen.