Time
Distance
Time period
Light intensity
The billions of stars and other heavenly bodies in the universe are separated by such a large distances, so the ordinary units for measuring distances on earth i.e. metres, kilometers or miles are not adequate for the purpose.
For measuring these extremely large distances, we use two astronomical units, the light year and the parsec.
A light year is defined as the distance travelled by light in one year. Light-year is the unit of length to measure large distances (astronomical distances). The total distance travelled by light in a year is called 1 light year.
The speed of light is 300,000 km/s and 1 year has 1 × 365 × 24 × 60 × 60 seconds.
∴ 1 Light year = 300.000 × 365 × 24 × 60 × 60 km
1 Light year = 9.46 × 1012 km.
Another unit commonly used for measuring astronomical distances is the parsec.
1 parsec is equal to 3.26 light years.
The distance travelled by the light at a speed of 300,000 km/s in one minute (60 seconds) is called a light minute.
1 light minute = 300,000 km/s × 1 minute = 300,000 km/s × 60 sec = 18,000,000 km = 18 × 106 km.
Related MCQs
- Who is Francois Fillon? (CSS 2010 Current Affairs Paper)
- Prime Minister of Italy
- President of Germany
- Foreign Minister of France
- None of these
Submitted by: CSS Exam Desk Team
- Iran US Nuclear Deal was signed in which year? (CSS 2018 Current Affairs Paper)
- 2014
- 2015
- 2016
- None of the above
Submitted by: CSS Exam Desk Team
- The word ceramic means? (CSS 2014 General Science & Ability Paper)
- Hard material
- Hard material
- Dry material
- Burnt material
Submitted by: CSS Exam Desk Team
- The fuel used in rockets is? (CSS 2015 General Science & Ability Paper)
- Liquid oxygen
- Nitrogen tetra oxide
- Hydrogen peroxide
- All of these
Submitted by: CSS Exam Desk Team
- Diamer-Bhasha Dam has been planned on the river? (CSS 2011 Current Affairs Paper)
- Jhelum
- Chenab
- Indus
- None of these
Submitted by: CSS Exam Desk Team
- Yaum-e-Nahar is on? (CSS 2014 Islamic Studies Paper)
- 10th Zil Hajj
- 11th Zil Hajj
- 12th Zil Hajj
- None of these
Submitted by: CSS Exam Desk Team
- When simla conference was concluded with failure? (CSS 2010 Pakistan Affairs Paper)
- June14,1945
- June14,1945
- Aug14,1945
- None of these
Submitted by: CSS Exam Desk Team
- Who was Dr. Fazlur Rehman? (CSS 2023 Special Pakistan Affairs Paper)
- A religious scholar
- A political scientist
- A religious political leader
- None of these given options
Submitted by: CSS Exam Desk Team
- Hujjatullah-il-Baligha was written by? (CSS 2015 Pakistan Affairs Paper)
- Shah Walliullah Dehlavi
- Syed Ahmed Brailvi
- Sir Syed Ahmaed Khan
- None of these
Submitted by: CSS Exam Desk Team
- Cyclones? (CSS 2018 General Science & Ability Paper)
- Experience Coriolis effects that deflect air to the right in the Southern Hemisphere
- Are associated with Super geostrophic winds
- Are typically regions of fair weather?
- Are associated with Low pressure systems
Submitted by: CSS Exam Desk Team
- The British Parliament announced the Independence Act on? (CSS 2015 Pakistan Affairs Paper)
- 14 July 1947
- 15 July 1947
- 18 July 1947
- None of these
Submitted by: CSS Exam Desk Team
- The SYNONYM of the word \"PLACID\" is? (CSS 2018 English Precis & Composition Paper)
- Stormy
- Tranquil
- Excitable
- Temperamental
Submitted by: CSS Exam Desk Team
- Who called back M. Bin Qasim? (CSS 2022 Pakistan Affairs Paper)
- Walid bin Abdul Malik
- Sulaiman Bin Abdul Malik
- Muhammad Ghuri
- None of these
Submitted by: CSS Exam Desk Team
- Which one is not a part of cell phone memory? (CSS 2022 General Science & Ability Paper)
- LCD
- Battery
- Water
- None of these
Submitted by: CSS Exam Desk Team
- Ombrophobia is fear of? (CSS 2015 General Science & Ability Paper)
- Rain
- Snow
- Smog
- None of these
Submitted by: CSS Exam Desk Team
- \"Mujadid-Alf-Thani\" is the title of? (CSS 2024 Islamic Studies Paper)
- Shah Wali Ullah
- Abdul Haq Muhadith dehlvai
- Sheikh Ahmad Sarhandi
- Sheikh Mohayudin ibn Arabi
Submitted by: CSS Exam Desk Team
- In which month does the UN General Assembly usually meet every year? (CSS 2009 Current Affairs Paper)
- August
- September
- October
- November
Submitted by: CSS Exam Desk Team
- The SYNONYM of the word \"SONOROUS\" is? (CSS 2014 English Precis & Composition Paper)
- Loud
- Heavy
- Bright
- Sleepy
Submitted by: CSS Exam Desk Team
- The Pilgrams are gathered in Arafat on? (CSS 2023 Special Islamic Studies Paper)
- 30th Zilqada
- 9th Zihlajj
- 10th Zilhajj
- 11th Zilhajj
Submitted by: CSS Exam Desk Team
- Sunlight can reach a depth of how many meters in the ocean? (CSS 2013 General Science & Ability Paper)
- 80 meters
- 100 meters
- 120 meters
- 200 meters
Submitted by: CSS Exam Desk Team
- The Shape of the Earth is? (CSS 2015 General Science & Ability Paper)
- Spherical
- Ellipsoid
- Round
- None of these
Submitted by: CSS Exam Desk Team
- In a railway track, two rails are joined end to end with a gap in between them because: (CSS 2009 General Science & Ability Paper)
- Steel can be saved.
- Accidents due to contraction in winter can be avoided.
- Air gaps are necessary for bearing the weight of running train.
- Accidents due to expansion in summer can be avoided.
Submitted by: CSS Exam Desk Team
- How many official working languages are recognized by UNO? (CSS 2009 Current Affairs Paper)
- 8
- 6
- 4
- None of these
Submitted by: CSS Exam Desk Team
- “The Reconstruction of Religious Thought” written by? (CSS 2016 Current Affairs Paper)
- Ahmed Ali
- Allama Muhammad Iqbal
- Javed Majeed
- None of these
Submitted by: CSS Exam Desk Team
- Which amendment declared Qadiani as Non- Muslims? (CSS 2022 Pakistan Affairs Paper)
- 2nd
- 3rd
- 4th
- None of these
Submitted by: CSS Exam Desk Team