Give a reason for each of the following :
i. Delhi has rain in December - January.
ii. Kolkata has a little rain in Apri.
i. Due to western disturbances which originate in areas near the Mediterranean Sea.
ii. Due to North westerns thunderstorm.
The dependency ratio is higher in rural areas than in UIrban areas. Give two reasons to explain why.
i. What is meant by variability of rainfall ?
ii. How does this variability affect agriculture ?
Mention two different ways by which modern methods of irrigation are an improvement over the primitive methods.
i. Name two cities in India which have grown rapidly due to in -migration.
ii. What are the two factors that led to the decreasing growth rate of population from 1981 to 2001 ?