Question

 What does an electric circuit mean ? Name a device that helps to maintain a potential di{ference across a conductor in a circuit. When do we say that the potential difference across a conductor is 1 volt ? Calculate the amount work done in shifting a charge of 2 coulombs from a point A to B having potentials 110 V and 25 V respectively.

Answer 1

Electric circuit : The closed path along which an electric current flows is called an ‘electric circuit’. The device that helps to maintain a potential difference across a conductor in a circuit are : electric cell, electric battery, electric generator.
1 Volt : The potential difference between two points in an electric field is said to one volt if one joule
of work has to be done in bringing a positive charge of one coulomb from one point to another.
1 Volt =1Joule/1Coulomb  or 1 V =1J/1C
Work done = V (Potential difference) × Q (Coulombs)
W = V × Q
= 85 × 2 = 170 Joule