Why did industrial production in India increase during the First World War?

Explanation

As the British mills were busy with the First World War production to meet the needs of the army, Manchester imports into India declined. Then the Indian industrial growths suddenly shoot up. The reasons behind the growth were -
(i) With the decline of imports suddenly, Indians mills had a vast domestic market to supply their products.
(ii) As the war prolonged, Indian factories were called upon to supply for war needs also, such as jute bags, cloth for uniforms of soldiers, tents, leather boots etc., and many other items.
(iii) New factories were set up and old ones organised multiple shifts, many new workers were employed and everyone was made to work for longer hours during the war years. As a result, Indian industries boomed.