Circuit Theory

Unit of voltage is/are

a) volt

b) joules/coloumb

c) Nm/C

d) All the above

Correct Answer: Option D

Solution:

Voltage is nothing but how much Work-done is needed in moving a unit charge from infinity to a point against the influence of electric field. 

Voltage = Work-done per unit charge$$V (t)=\frac {dW}{dq}$$ 

Unit:

• volt (V) 
• Joules/Coloumb (since work-done per unit charge) 
• Also, Work done = Force × distance, hence unit of voltage can be Nm/C (Newton - metre / Coloumb)