The each twist of twisted wires generates magnetic field that is opposite to its neighboring one. That is why the EMI (Electromagnetic Interference Effect) is reduced.

we are using battery to store electricity in the form of voltage ? and when current is drawn from batteries we use electricity in the form of electrical power p...

The internal resistance of a voltage source is connected in series, due to this internal resistor the o/p voltage is less than its said value (like 5 Volt battery). and...