Question

What does an electric circuit mean ? Name a device that helps to maintain a potential difference across a conductor in a circuit. When do we say that the potential difference across a conductor is 1 volt ? Calculate the amount of 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 be one volt if one joule of work is done in moving one coulomb of electric charge from one point to another.

1 volt = 1 joule/ 1 Coulomb or 1 V = 1 J /1 C 

Work done = V (Potential difference) × Q (Coulombs) 

W = V × Q 

 = 85 × 2 

 = 170 Joule.