The way phonegap apps typically do this is via plugins.
You can find more info on how to write your plugin here Plugin Development Guide - Apache Cordova
Once you take that approach, you can let cordova.exec do the heavy lifting for you.
You can also dig into the way cordova works in the apache/cordova-ios repo.
also kindly clarify me...Is it possible that I can have part of the application in cordovan web view and its plugin and remaining parts in native sdk.
You can have as many plugins installed as you like. Do keep in mind that plugins aren't free from the perspective of resources or privileges, so you should always limit the plugins installed to the ones you actually need.
You can also embed Cordova into a native app, although this workflow is a bit more advanced than the typical CLI workflow.