Authentic Classroom Explanation by IAS Monk

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📍 The Question

On June 21 every year, which of the following latitude(s) experience(s) sunlight of more than 12 hours?

1. Equator
2. Tropic of Cancer
3. Tropic of Capricorn
4. Arctic Circle

Select the correct answer using the code given below:

(a) 1 only
(b) 2 only
(c) 3 and 4
(d) 2 and 4

Correct Answer: (d) 2 and 4

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🎯 Theme of the Question

Physical Geography | Earth–Sun Relationship | Solstices | Length of Day

This is a classic NCERT-based conceptual question, testing understanding of the Summer Solstice (21 June) and its impact on day length across latitudes.

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🧠 Classroom Explanation

Let us first recall the astronomical setting.

• The Earth’s axis is tilted at 23½° from the vertical
• Consequently, it makes an angle of 66½° with the plane of the Earth’s orbit
• Due to this axial tilt, the distribution of sunlight varies through the year

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🌞 What happens on 21 June?

• The Northern Hemisphere is tilted towards the Sun
• The Sun’s vertical (direct) rays fall on the Tropic of Cancer (23½° N)
• This position is called the Summer Solstice in the Northern Hemisphere

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🔍 Now, examine each latitude

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🔹 1. Equator ❌

• The Equator receives nearly equal day and night throughout the year
• On June 21, day length is approximately 12 hours
• It does not exceed 12 hours

✘ Not correct

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🔹 2. Tropic of Cancer ✅

• Receives vertical rays of the Sun on June 21
• Experiences:
  • Longest day
  • Shortest night
• Day length is more than 12 hours

✔️ Correct

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🔹 3. Tropic of Capricorn ❌

• Located in the Southern Hemisphere
• On June 21:
  • Southern Hemisphere is tilted away from the Sun
  • Days are shorter than nights

✘ Not correct

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🔹 4. Arctic Circle ✅

• On June 21:
  • The North Pole is inclined towards the Sun
  • Areas north of the Arctic Circle experience continuous daylight
• This phenomenon is known as the Midnight Sun

✔️ Correct

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📊 Final Assessment

Latitude	Day length on June 21
Equator	≈ 12 hours ❌
Tropic of Cancer	> 12 hours ✅
Tropic of Capricorn	< 12 hours ❌
Arctic Circle	> 12 hours (continuous daylight) ✅

👉 Correct answer: (d) 2 and 4

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❌ UPSC Elimination Logic

• UPSC expects clarity on:
  • Axial tilt
  • Solstices vs Equinoxes
• Equator is a common trap (equal days)
• Polar regions behave extremely during solstices

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🧩 Memory Hook

“June leans north — Cancer burns, the Arctic never sleeps.”

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🧠 Prelims Strategy Insight

For day-length questions:

• June 21 → Northern Hemisphere advantage
• December 22 → Southern Hemisphere advantage
• Equator stays neutral all year

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🧭 IAS Monk Whisper

When the Earth tilts, time itself stretches or shrinks with latitude.