The question asks to identify which option is NOT a component of the Solar System. We need to recall the definition and constituents of the Solar System.
Correct Option: B) Constellations
The question asks for the general term used to describe a body that revolves around another body. This is a fundamental concept in astronomy and physics related to celestial mechanics.
Correct Option: A) Satellite
A satellite is defined as any object that revolves around another, usually larger, object. This can be a natural celestial body (like a moon orbiting a planet or a planet orbiting a star) or an artificial object (like a communication satellite orbiting Earth).
The question asks to identify which of the given countries possesses its own operational satellite navigation system. This requires knowledge of global navigation satellite systems (GNSS) and the countries that have developed and deployed them.
Major global satellite navigation systems include:
Major regional satellite navigation systems include:
Based on this information, Japan is the only country among the options that has its own satellite navigation system (QZSS).
D) Japan — Japan operates the Quasi-Zenith Satellite System (QZSS), also known as Michibiki. While it augments GPS, it also provides independent positioning services, making it Japan's own satellite navigation system.
The question asks us to identify the correct statements about the Sun and astronomical distances. We need to evaluate each statement individually based on established astronomical facts and definitions.
The average distance between the Earth and the Sun is approximately 149.6 million kilometers, often rounded to 150 million km. This distance is also defined as 1 Astronomical Unit (AU).
We know the speed of light \(c \approx 3 \times 10^8 \text{ m/s}\) or \(300,000 \text{ km/s}\). The distance from the Sun to Earth is approximately \(150 \times 10^6 \text{ km}\).
Time taken for light to travel from Sun to Earth:
\[ \text{Time} = \frac{\text{Distance}}{\text{Speed}} = \frac{150 \times 10^6 \text{ km}}{300,000 \text{ km/s}} = 500 \text{ seconds} \]To convert this to minutes:
\[ 500 \text{ seconds} \times \frac{1 \text{ minute}}{60 \text{ seconds}} \approx 8.33 \text{ minutes} \]So, approximately 8 light minutes is a correct representation of the distance.
This is the standard definition of a light-year. A light-year is a unit of distance, not time, and it represents the distance that light travels in a vacuum in one Julian year (365.25 days).
Alpha Centauri is the closest star system to the Sun. Its distance from Earth is approximately 4.37 light-years. Therefore, stating it is about 4.3 light-years is accurate.
Since all four statements are factually correct, the option that includes all of them is the correct answer.
D) All the above — All statements (i), (ii), (iii), and (iv) are correct based on astronomical facts and definitions.
| List I | List II |
| a) Inner planets | 1.) Moon |
| b) Outer planets | 2.) Great Bear |
| c) Constellation | 3.) Saturn |
| d) Satellite of Earth | 4.) Mars |
The question asks to match items from List I (astronomical terms) with their corresponding examples from List II. We need to identify the correct pairing for inner planets, outer planets, constellations, and the Earth's satellite.
A) a-4,b-3,c-2,d-1. This option correctly matches all the given items based on the definitions and examples.
The question asks to identify the correct reason(s) for the phases of the moon. We need to evaluate each given statement to determine its validity in explaining lunar phases.
A) (i) only. Statement (i) correctly explains that the phases of the moon are due to the changing perspective from Earth of the sunlit portion of the moon as it orbits our planet.