Angular2 If ngModel is used within a form tag, either the name attribute must be set or the form

Question

I am getting this error from Angular 2

core.umd.js:5995 EXCEPTION: Uncaught (in promise): Error: Error in app/model_exposure_currencies/model_exposure_cu

Answer 1

As every developer have a common habit, not to read the complete error, just read the first line and start looking for answer from someone else :):) I am also one of them, that's why I am here:

Read the error, clearly saying:

Example 1: 
Example 2: 

What more we need to understand this error?

Use any one option everything will work smooth.