The time period while traveling from Delhi to Ludhiana is about 5 hours. You can directly catch the bus from Delhi and reach down to Ludhiana.
The time period while traveling from Delhi to Ludhiana is about 4 hours and 35 minutes. Take the train from the Delhi station and it will drop you at the Ludhiana railway station.
For traveling to Ludhiana from Delhi, you need to take a flight from Delhi which will land in Chandigarh airport. From Chandigarh, you can take a bus to reach Ludhiana. From Delhi to Chandigarh, it will take approx 50 minutes from the flight. And from Chandigarh to Ludhiana, it will take around 1 hour 45 min.