Day & Night Archives

1. Longest day/night is experienced during a year in the

Longest day/night is experienced during a year in the

Equator

Pole

Tropics of Cancer/Capricorn

Arctic/Antarctic Circle

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Answer is Wrong!

This question was previously asked in

UPSC CISF-AC-EXE – 2017

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The length of day and night varies significantly with latitude due to the tilt of the Earth’s axis relative to its orbital plane. The maximum variation occurs at the poles (North and South Poles). At the poles, during summer, there is continuous daylight for approximately six months (polar day), and during winter, there is continuous darkness for approximately six months (polar night). This represents the absolute extreme in terms of the duration of continuous day or night experienced during a year. The question asks for the location where the “Longest day/night is experienced during a year”, which refers to the maximum possible duration of either daylight or darkness.

– The Earth’s axial tilt causes seasons and variation in day/night length with latitude.
– The variation is minimal at the equator (always around 12 hours day/night).
– The variation increases towards the poles.
– The poles experience the most extreme variations, including prolonged periods of continuous daylight or darkness.

At the Arctic and Antarctic Circles (approx 66.5° latitude), the sun does not set on the summer solstice (24 hours of daylight) and does not rise on the winter solstice (24 hours of darkness). However, this is a 24-hour period, whereas at the poles, the period extends to roughly six months. Thus, the pole experiences the *longest* continuous day or night period.

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2. On June 21 every year, which of the following latitude(s) experience(s

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

Equator
Tropic of Cancer
Tropic of Capricorn
Arctic Circle

Select the correct answer using the code given below :

1 only

2 only

3 and 4

2 and 4

Answer is Right!

Answer is Wrong!

This question was previously asked in

UPSC IAS – 2024

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June 21st marks the Summer Solstice in the Northern Hemisphere. On this day, the Earth’s Northern Hemisphere is maximally tilted towards the sun.
– Equator (0° latitude): Experiences roughly 12 hours of daylight and 12 hours of night throughout the year, including on June 21st. Sunlight duration is approximately 12 hours, not more than 12 hours.
– Tropic of Cancer (approx 23.5° N): On June 21st, the sun is directly overhead at noon at the Tropic of Cancer. All locations in the Northern Hemisphere north of the equator experience more than 12 hours of daylight on this day. The closer to the North Pole, the longer the daylight. So, the Tropic of Cancer experiences more than 12 hours.
– Tropic of Capricorn (approx 23.5° S): June 21st is the Winter Solstice in the Southern Hemisphere. Locations south of the equator experience less than 12 hours of daylight on this day (except south of the Antarctic Circle, which has 24 hours of darkness). So, the Tropic of Capricorn experiences less than 12 hours.
– Arctic Circle (approx 66.5° N): On June 21st, all locations north of the Arctic Circle experience 24 hours of daylight (Midnight Sun). 24 hours is definitely more than 12 hours.
Therefore, the Tropic of Cancer and the Arctic Circle experience sunlight of more than 12 hours on June 21st.

On the Northern Hemisphere Summer Solstice (June 21st), all latitudes in the Northern Hemisphere north of the equator experience more than 12 hours of daylight; the duration increases with latitude.

The phenomenon of polar day (24 hours of sunlight) occurs north of the Arctic Circle on June 21st. The duration of daylight increases from 12 hours at the equator to 24 hours at or north of the Arctic Circle on this day.

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3. In the northern hemisphere, the longest day of the year normally occur

In the northern hemisphere, the longest day of the year normally occurs in the :

First half of the month of June

Second half of the month of June

First half of the month of July

Second half of the month of July

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Answer is Wrong!

This question was previously asked in

UPSC IAS – 2022

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The longest day of the year in the Northern Hemisphere, known as the Summer Solstice, normally occurs in the second half of the month of June.

The Summer Solstice occurs around June 20th or 21st each year, when the Northern Hemisphere is tilted most directly towards the Sun.

Conversely, the shortest day in the Northern Hemisphere (Winter Solstice) occurs around December 21st or 22nd. In the Southern Hemisphere, the longest day is around December 21st or 22nd, and the shortest day is around June 20th or 21st.

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4. On 21st June, the Sun

On 21st June, the Sun

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does not set below the horizon at the Arctic Circle

does not set below the horizon at the Antarctic Circle

shines vertically overhead at noon on the Equator

shines vertically overhead at the Tropic of Capricorn

Answer is Right!

Answer is Wrong!

This question was previously asked in

UPSC IAS – 2019

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Option A is correct. On June 21st, which is the summer solstice in the Northern Hemisphere, the Sun is directly overhead at the Tropic of Cancer (23.5° N). As a result, areas north of the Arctic Circle (66.5° N) experience 24 hours of daylight, meaning the sun does not set below the horizon.

– June 21st is the summer solstice in the Northern Hemisphere.
– The Sun’s rays are vertical over the Tropic of Cancer (23.5° N) on this day.
– Regions north of the Arctic Circle (66.5° N) experience the “midnight sun” (24 hours of daylight).

– On the same day, the Antarctic Circle (66.5° S) experiences 24 hours of darkness because it is winter in the Southern Hemisphere.
– The Sun is directly overhead at the Equator only during the equinoxes (around March 20/21 and September 22/23).
– The Sun is directly overhead at the Tropic of Capricorn (23.5° S) during the winter solstice in the Northern Hemisphere (around December 21/22).

5. Variations in the length of daytime and nighttime from season to seaso

Variations in the length of daytime and nighttime from season to season are due to

the earth's rotation on its axis

the earth's revolution round the sun in an elliptical manner

latitudinal position of the place

revolution of the earth on a tilted axis

Answer is Right!

Answer is Wrong!

This question was previously asked in

UPSC IAS – 2013

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The correct option is D, stating that the variation in the length of daytime and nighttime from season to season is due to the revolution of the earth on a tilted axis.

– The Earth’s axis is tilted at an angle of approximately 23.5 degrees relative to its orbital plane around the sun.
– As the Earth revolves around the sun, this tilt causes different parts of the Earth to be inclined towards or away from the sun at different times of the year.
– When a hemisphere is tilted towards the sun, it receives more direct sunlight and experiences longer days and shorter nights (summer). When it is tilted away from the sun, it receives less direct sunlight and experiences shorter days and longer nights (winter).
– The Earth’s rotation on its axis causes the daily cycle of day and night, but not the seasonal variation in their lengths.
– The elliptical orbit affects the Earth’s distance from the sun, influencing the intensity of sunlight and subtly affecting orbital speed, but the seasonal variation in day length is primarily due to the axial tilt.
– Latitudinal position influences the *magnitude* of the variation; the variation is minimal at the equator and maximal at the poles, but the underlying cause is the axial tilt and revolution.

This tilt is responsible for the occurrence of seasons and the varying angle of the sun in the sky throughout the year, in addition to the variation in day length.

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6. The shortest day length that occurs in the Northern hemisphere is on

The shortest day length that occurs in the Northern hemisphere is on

21st March

23rd September

22nd November

22nd December

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Answer is Wrong!

This question was previously asked in

UPSC NDA-2 – 2017

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The shortest day length in the Northern Hemisphere occurs around December 22nd.

This date marks the winter solstice in the Northern Hemisphere, when the Earth’s North Pole is tilted furthest away from the Sun, resulting in the fewest hours of daylight.

March 21st (Vernal Equinox) and September 23rd (Autumnal Equinox) are approximate dates when day and night are of roughly equal length everywhere on Earth. The exact date of the solstice can vary by a day or two depending on the year.

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