Northern Plains is a vast region located in the northern part of India. It stretches from the foothills of the Himalayas in the north to the Deccan plateau in the south. The total length of the Northern Plains is approximately 2400 km.

Explanation:

Northern Plains:
The Northern Plains is a geographical region that encompasses several states of India, including Punjab, Haryana, Delhi, Uttar Pradesh, Bihar, and parts of Rajasthan. It is a fertile and densely populated region known for its agricultural productivity.

Length of the Northern Plains:
The total length of the Northern Plains can be measured from the foothills of the Himalayas in the north to the point where it meets the Deccan plateau in the south. This length is approximately 2400 km.

Importance of the Northern Plains:
The Northern Plains are of great significance due to their fertile soil, which supports extensive agriculture. The region is known as the "granary of India" as it produces a significant portion of the country's food grains. The fertile alluvial soil in the plains is ideal for growing crops like wheat, rice, sugarcane, cotton, and oilseeds.

The plains are also crisscrossed by several major rivers, including the Ganges, Yamuna, Brahmaputra, and their tributaries. These rivers provide a constant water supply for irrigation and contribute to the overall agricultural productivity of the region.

Additionally, the Northern Plains serve as a major transportation and communication corridor, with several important cities and towns located along its length. The region is well-connected by road, rail, and air networks, facilitating trade and commerce.

Conclusion:
In conclusion, the total length of the Northern Plains is approximately 2400 km. This vast stretch of fertile land plays a crucial role in India's agricultural and economic development.