This is the query to find the physical location for backed up database file.
SELECT
physical_device_name,
backup_start_date,
backup_finish_date,
backup_size/1024.0 AS BackupSizeKB
FROM msdb.dbo.backupset bs
INNER JOIN msdb.dbo.backupmediafamily bm ON bs.media_set_id = bm.media_set_id
WHERE database_name = 'Testdb'
ORDER BY backup_finish_date DESC
Output :
SELECT
physical_device_name,
backup_start_date,
backup_finish_date,
backup_size/1024.0 AS BackupSizeKB
FROM msdb.dbo.backupset bs
INNER JOIN msdb.dbo.backupmediafamily bm ON bs.media_set_id = bm.media_set_id
WHERE database_name = 'Testdb'
ORDER BY backup_finish_date DESC
Output :