Alternatives to using custom methods for angularjs $http.get in an ASP.Net Web Api 2 controller

Its very simple.

Note: I don't understand your first question properly. for 2que and 3que....

Lets say I'm using Get Method in Web api 2, MVC5 (I hope your are clear with HTTP methods in web api) Which collects required data (to be returned back to angularjs)..... Now it depends upon your requirement that how many objects you want to send back to client side.

IHttpActionResult would be your return type in all HTTP methods as IHttpActionResult sends Status code via Web api....

eg;

Lets say I have PrescriptionsController.cs. So in it.

[HttpGet]
public IHttpActionResult Get()
{
      var appointment1 = from prescription in db.Prescriptions
                       where prescription.appointment == "15/01/2015"
                       from consultation in prescription.Consultations

                       select new
                       {
                           ID = prescription.id,
                           Name = prescription.patient_name,
                           Contact = prescription.patient_contact,
                           Task = prescription.next_task
                       };

    var appointment2 = from consultation in db.Consultations
                       where consultation.next_date == "15/01/2015"
                       select new
                       {
                           ID = consultation.Prescription.id,
                           Name = consultation.Prescription.patient_name,
                           Contact = consultation.Prescription.patient_contact,
                           Task = consultation.next_task
                       };

    var finalAppointments = appointment1.Concat(appointment2);
   // return finalAppointments;    //rather I'd use below line...

      return Ok(finalAppointments); // here your are concatenating two objects and want to send single object only.

}

Lets say I want to send two objects separately... then use following way,

[HttpGet]
//public IHttpActionResult Get()
public dynamic Get()
{
      var appointment1 = from prescription in db.Prescriptions
                       where prescription.appointment == "15/01/2015"
                       from consultation in prescription.Consultations

                       select new
                       {
                           ID = prescription.id,
                           Name = prescription.patient_name,
                           Contact = prescription.patient_contact,
                           Task = prescription.next_task
                       };

    var appointment2 = from consultation in db.Consultations
                       where consultation.next_date == "15/01/2015"
                       select new
                       {
                           ID = consultation.Prescription.id,
                           Name = consultation.Prescription.patient_name,
                           Contact = consultation.Prescription.patient_contact,
                           Task = consultation.next_task
                       };

    //var finalAppointments = appointment1.Concat(appointment2);
   // return finalAppointments;    //rather I'd use below line...

   //   return Ok(finalAppointments); // here your are concatenating two objects.

   return new {appointment1 ,appointment2 }; // you can send multiple objects...

}

Any query feel free to ask.