Why phi component is not taken into account for vector R ?See attachment.

[Saurabh Sharma]

Why phi component is not taken into account while calculation electric field intensity due to line charge?See attachment for details.https://physicsforums-bernhardtmediall.netdna-ssl.com/data/attachments/74/74211-22d26b27211fd4b186955b890458804e.jpg https://physicsforums-bernhardtmediall.netdna-ssl.com/data/attachments/74/74212-c0d171ced27ce079690ae1924ecc7a04.jpg

 

[Orodruin]

The position vector in cylinder coordinates does not have a $\varphi$ component, it is given by $\vec r = \rho \vec e_\rho + z\vec e_z$.

 

[Saurabh Sharma]

The position vector in cylinder coordinates does not have a $\varphi$ component, it is given by $\vec r = \rho \vec e_\rho + z\vec e_z$.

Thanks for you help.