Johannes Kepler, through meticulous observations and profound reasoning, presented to the world a trio of laws that explained the motion of planets around the Sun. These laws not only laid down the foundation for Newton’s law of gravitation but also provided a clearer understanding of our place in the vast cosmos. For every NEET aspirant aiming to conquer the universe of Physics, understanding these laws is crucial. Dive into the planetary motion with these 15 simplified MCQs tailored especially for your NEET preparations.
1. Which of Kepler’s laws states that all planets move in elliptical orbits with the Sun at one of the foci?
Answer:
Explanation:
Kepler's First Law, also known as the Law of Ellipses, states this principle.
2. According to Kepler's Second Law, a line segment joining a planet to the Sun sweeps out equal areas during equal intervals of:
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Explanation:
This is the Law of Equal Areas which suggests planets move faster when closer to the Sun in their orbit.
3. Kepler's Third Law relates which of the following?
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Explanation:
The Third Law, or the Law of Harmonies, states that the square of the orbital period of a planet is directly proportional to the cube of the semi-major axis of its orbit.
4. Kepler's Laws of Planetary Motion were derived from observations made primarily by which astronomer?
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Explanation:
Kepler used the detailed and accurate observations of Tycho Brahe to formulate his laws.
5. A planet is in its closest approach to the Sun in its orbit. This position is termed as:
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Explanation:
Perihelion is the point in a planet's orbit where it is nearest to the Sun.
6. The larger the orbit of a planet around the Sun, the ________ the planet's average speed.
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Explanation:
By Kepler's second law, planets further from the Sun have slower average speeds.
7. The orbits of most planets in our solar system are:
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Explanation:
While the orbits are elliptical, they are nearly circular for most planets, meaning they have low eccentricities.
8. The force responsible for keeping the planets in their elliptical orbit is:
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Explanation:
The gravitational pull from the Sun keeps the planets in their orbits.
9. If a planet takes 4 years to orbit the Sun, how long would a planet take that is twice as far from the Sun?
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Explanation:
Using Kepler's Third Law, the period will increase by the cube root of 2^3 multiplied by the original period, which is 2.83 times 4.
10. What does the eccentricity of an orbit indicate?
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Explanation:
Eccentricity gives a measure of how elliptic (or deviated from a perfect circle) an orbit is.
11. Which planet has the most elliptical orbit in our solar system?
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Explanation:
Mercury has the highest eccentricity among the planets in our solar system.
12. For a planet in orbit, the point furthest from the Sun is called:
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Explanation:
Aphelion is the point in a planet's orbit where it is farthest from the Sun.
13. Kepler's laws apply to:
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Explanation:
Kepler's laws, though formulated for our solar system, apply to all objects under the influence of gravitational forces, including moons, asteroids, and even artificial satellites.
14. The time taken by Mars to orbit the Sun is approximately:
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Explanation:
Mars has an orbital period of about 687 Earth days.