Unity3D Physics.Raycast() never true

Question

I have a scene where I have an game object with sprite renderer and image attached to it. The game object has a 2D collider to. I'm trying to get a true reading when I'm clicking the image but its always false, I have no idea what em i doing wrong.

 TapPos = GetComponent<Camera> ().ScreenToWorldPoint (new Vector3 (Input.mousePosition.x, Input.mousePosition.y, 0));   

 bool SomethingTapped(){

    Vector3 CanvasTapPoint = new Vector3 (TapPos.x, TapPos.y, 10);
    Debug.DrawLine (TapPos, CanvasTapPoint, Color.green, 10f);

    if (Physics.Raycast (TapPos,CanvasTapPoint, 20f)) {
        return true;
    } else
        return false;
}

PS:

• The Debug.DrawLine goes right through my sprite.

• The script is on the camera and the camera Z position is -10

EDIT After Andrew Griffin's response changed my code to this if anyone want to do the same thing:

    public Transform ObjectTapped(){

    RaycastHit2D FoundObj = Physics2D.Raycast(TapPos, new Vector2(TapPos.x, TapPos.y + 1),0f);

    if(FoundObj.collider  != null){
        Transform obj = FoundObj.transform;
        return obj;
    }
    else{
        return null;
    }
}

Answer 1

Look into Physics2D.Raycast. As far as I am aware, Physics.Raycast will not work with 2D colliders. You must use Physics2D.Raycast instead.