Which broad part of India receives the maximum annual insolation because of its tropical location and generally clearer skies?

Introduction / Context:
Insolation means incoming solar radiation received at the earth surface. Different parts of India receive different amounts of insolation depending on latitude, cloud cover and atmospheric conditions. This question asks which broad region of the country receives the maximum insolation on average, a concept that is useful for climate, agriculture and solar energy planning.

Given Data / Assumptions:
• The focus is on broad parts of India such as north, south, east and west. • We must identify which part receives maximum insolation. • Options specify cardinal regions of the country. • We assume long term average conditions, not one particular day.

Concept / Approach:
Regions closer to the equator receive a higher angle of incoming solar radiation and generally higher insolation, provided cloud cover is not excessive. Southern India lies closer to the equator than northern India and remains in the tropics throughout the year. Therefore, the southern part of India tends to receive more insolation on average compared with northern or eastern regions.

Step-by-Step Solution:
Step 1: Note that the Tropic of Cancer passes roughly through central India, so regions south of this line lie closer to the equator. Step 2: Southern states like Tamil Nadu, Karnataka, Andhra Pradesh and Kerala remain in the tropical zone and receive high sun angles for most of the year. Step 3: Northern India moves further away from the equator and has more pronounced seasonal variations, reducing average annual insolation slightly. Step 4: While some parts of western India are sunny and arid, the overall regional classification for maximum insolation in textbooks points to southern India. Step 5: Therefore, we choose the southern part of India as the correct answer.

Verification / Alternative check:
Climatology text and exam keys often directly state that southern India receives higher insolation because of its lower latitude. Solar energy potential maps show significant solar intensity across the Deccan and southern peninsula. Comparative discussions highlight that north India has more winter season with lower sun angles, reducing its annual average insolation versus the south.

Why Other Options Are Wrong:
Northern part of India: Located at higher latitudes and experiencing a cooler winter season with lower sun angles, which reduces annual insolation. Eastern part of India: Includes regions with substantial cloud cover due to monsoon and local conditions, not the maximum insolation zone. Western part of India: Has deserts with high sunshine but as a broad part of India is not consistently highlighted in textbooks as receiving maximum insolation compared with the south. Central part of India: Receives fairly high insolation but is not the region singled out in standard exam answers, which prefer southern India for maximum insolation.

Common Pitfalls:
Some candidates choose western India because of desert areas like Rajasthan with strong sunshine, but the question asks about broad parts of India, not individual local pockets. Another error is to ignore latitude and focus only on dryness or cloudiness. Remember that proximity to the equator is a key factor, and southern India fits that criterion best among the given options.

Final Answer:
The broad region of India that receives maximum annual insolation is the southern part of India.