Logfile Class error "You cannot execute this operation since the object has not been created." - smo

Question

We wanted to automate few management operations for new SQL Server installation, so we started looking into
LogFile Class
But this class doesn't let us run the ALTER() method to change log file location. Also doesn't let us add a new file and drop and existing file. Anyone know the internals of this class :) ?
NOTE: I know we can run a SQL query and run ALTER DATABASE MODIFY FILE and copy files and restart db. This question is specific to this class.
I also tried to alter an existing file instead of creating a new one and dropping existing one , and it throws the same error.
ERROR
"{"Drop failed for LogFile 'DBAUtility_log'. "}"
{"You cannot execute this operation since the object has not been created."}
class Program
{
static void Main(string[] args)
{
Server srv = new Server("xx");
Database db = default(Database);
db = srv.Databases["DBAUtility"];
//LogFile LF = new LogFile(srv.Databases.ItemById(0),'DBAUtility_log');
//Console.WriteLine("DB:", srv.Databases.Count());
Console.WriteLine(srv.Name);
Console.WriteLine("DBName" + srv.Databases.ItemById(5).ToString());
LogFile lf = new LogFile();
Console.WriteLine("LF:" + lf.ToString());
lf.Parent = db;
lf.Name = "DBAUtility_NEWLOG";
lf.FileName = "M:\\DBFiles\\SQLlog\\1\\DBAUtility_1.ldf";
lf.Create();
LogFile lf2 = new LogFile();
lf2.Parent = db;
lf2.Name = "DBAUtility_log";
lf2.FileName = "C:\\Install\\DBAUtility_1.ldf";
lf2.Drop(); //ERROR HERE
}
}

Answer 1

Create a log file for this database
$LogFileName = $db.name + '_Log'
$LogFile = New-Object ('Microsoft.SqlServer.Management.SMO.LogFile') ($db, $LogFileName)
$db.LogFiles.Add($LogFile)
$LogFile.FileName = $LogFileName + '.ldf'
$LogFile.Size = $logfilesize * 1024
$LogFile.GrowthType = 'KB'
$LogFile.Growth = $logfilegrowth * 1024
$LogFile.MaxSize = -1
$db.Create()