Roll A Ball not working - any help is appreciated

The code is here

using UnityEngine;
using UnityEngine.UI;
using System.Collections;

public class PlayerController : MonoBehaviour {
public float speed=10;
//private CharacterController cc;
private Rigidbody rb;

void Start ()
{
rb=GetComponent<Rigidbody>();
// cc = GetComponent<CharacterController>();

}

void FixedUpdate ()
{
float moveHorizontal = Input.GetAxis("Horizontal");
float moveVertical = Input.GetAxis("Vertical");

Debug.Log("I am alive and H : " + moveHorizontal);

Debug.Log("I am alive and V : " + moveVertical);


Vector3 movement = new Vector3(moveHorizontal, 0.0f, moveVertical);


//speed value is set to 10 in the inspector
rb.AddForce(movement * speed);

//cc.Move(movement*speed);

}
}

Scenario 1:
Rigidbody : Doesnt't work

Scenario 2:
When I added CharacterController instead and unchecked Rigidbody it works fine but speed is not shown in the CharacterCountroller in inspector for the Player

Scenario 3
With rb uncommented and cc commented out and if CharacterController is still selected along with Rigidbody it still works.

Any help is appreciated