Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A): Mercury is the second farthest planet from the Sun.
Reason (R): Mercury is the smallest planet in the entire solar system.
In the light of the above statements, choose the most appropriate answer from the options given below:
(d) (A) is not correct but (R) is correct
Analyzing Assertion and Reason on Planet Mercury
Let's carefully examine the given Assertion (A) and Reason (R) about the planet Mercury and determine their accuracy.
Evaluating Assertion (A): Mercury's Position from the Sun
Assertion (A) states: Mercury is the second farthest planet from the Sun.
To evaluate this, we need to know the order of the planets from the Sun. The planets in order from the Sun are:
- Mercury
- Venus
- Earth
- Mars
- Jupiter
- Saturn
- Uranus
- Neptune
Based on this order, Mercury is the first planet from the Sun, meaning it is the closest planet, not the second farthest. The second farthest planet is Uranus.
Therefore, Assertion (A) is incorrect.
Evaluating Reason (R): Mercury's Size
Reason (R) states: Mercury is the smallest planet in the entire solar system.
We can compare the sizes of the planets in the solar system by their radius or mass. Let's look at approximate equatorial radii:
| Planet | Approximate Equatorial Radius (km) |
|---|---|
| Mercury | 2,439.7 |
| Venus | 6,051.8 |
| Earth | 6,378.1 |
| Mars | 3,389.5 |
| Jupiter | 71,492 |
| Saturn | 60,268 |
| Uranus | 25,559 |
| Neptune | 24,764 |
Comparing the radii, Mercury indeed has the smallest equatorial radius among all the planets. It is significantly smaller than Earth, Venus, and Mars, and much smaller than the gas giants (Jupiter, Saturn, Uranus, Neptune).
Therefore, Reason (R) is correct.
Conclusion: Analyzing Assertion and Reason Statements
We have determined that:
- Assertion (A) is incorrect (Mercury is the closest planet, not the second farthest).
- Reason (R) is correct (Mercury is the smallest planet).
Now, let's consider the relationship between the statements and the options provided.
- Option (a) says both are correct and R explains A. Incorrect because A is false.
- Option (b) says both are correct and R does not explain A. Incorrect because A is false.
- Option (c) says A is correct but R is not correct. Incorrect because A is false and R is correct.
- Option (d) says A is not correct but R is correct. This matches our findings.
Thus, the most appropriate answer is that Assertion (A) is not correct, but Reason (R) is correct.
Revision Table: Key Facts about Mercury
| Fact | Description | Correctness (R/A statements) |
|---|---|---|
| Position from Sun | Closest planet to the Sun (1st) | Contradicts Assertion (A) |
| Size | Smallest planet in the solar system | Confirms Reason (R) |
| Orbital Period | Shortest orbital period (about 88 Earth days) | Additional Info |
| Surface | Heavily cratered, similar to the Moon | Additional Info |
| Atmosphere | Very thin exosphere | Additional Info |
Additional Information on Solar System Planets
Understanding the properties of planets in our solar system is fundamental to astronomy.
- Planetary Order: The sequence of planets from the Sun is crucial for many questions about distances and positions. It is Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.
- Inner vs. Outer Planets: The solar system is often divided into inner rocky planets (Mercury, Venus, Earth, Mars) and outer gas giants (Jupiter, Saturn, Uranus, Neptune).
- Size Comparison: Jupiter is the largest planet by far, followed by Saturn, Uranus, Neptune. The inner planets are much smaller, with Mercury being the smallest.
- Assertion-Reason Questions: These questions test your knowledge of facts and the causal relationship between two statements. Always evaluate each statement independently first before considering the relationship.
Important Questions from Assertion and Reason
Given below are two statements:
Statement I: Arithmetic Progression is a sequence in which the addition of any two consecutive terms is a constant.
Statement II: In a Geometric Progression, the ratio of any term to its preceding term is a constant.
In the light of the above statements, choose the most appropriate answer from the options given below.
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A): The filament in an electric bulb does not burn up although its temperature is about 2700°C when it glows.
Reason (R): Bulb filament is made of tungsten.
In the light of the above statements, choose the most appropriate answer from the options given below.
Given below are two statements: one is labeled as Assertion (A) and the other is labeled as Reason (R).
Assertion (A): Diamond is used for cutting glass.
Reason (R): Diamond has a high refractive index.
Choose the most appropriate answer:
Given below are two statements: one is labeled as Assertion (A) and the other is labeled as Reason (R)
Assertion (A): Copper is used to make electrical wires.
Reason (R): Copper has very low electrical resistance.
In the light of the above statements, choose the correct answer from the options given below.
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A): Earth is the only planet known to have life.
Reason (R): Earth has an atmosphere which is a mixture of Oxygen, Nitrogen and Carbon dioxide.In the light of the above statements, choose the most appropriate answer from the options given below:
