Mr. Kumar
This sounds to me that he is not aware of ground return path.
True, Mr. Kumar I will be very thankfull If you can please put some more light on the above subject.
Mr. Kumar I want to ask you at the time when you just completed your B.E. did you know all about PCB design.
I am sure your answer is no. cause univeristies here in India do not teach PCB design in B.E. course.
Secondly for a Mechanical Engineer like me who has only working knowledge of microcontrollers & digital electronics PCB design concept are not so easy to grasp. But still I am trying hard to learn the things & I am sure I will learn. I look forward for help of you guys for this. Thank you very much.

Regards,
Prahlad Purohit