Advertisements
Advertisements
प्रश्न
The orbit of a planet revolving around a star is ______.
विकल्प
circular
linear
towards the focal point
elliptical
Advertisements
उत्तर
The orbit of a planet revolving around a star is elliptical.
Explanation:
The planet’s distance from the star changes as it follows an elliptical path (so orbits are not perfectly circular). Because of this, the planet moves faster when it is nearer the star and slower when it is farther away (Kepler’s second law).
APPEARS IN
संबंधित प्रश्न
Identify the law shown in the figure and state three respective laws.

Observe the given figure showing the orbit of a planet moving around the Sun and write the three laws related to it:

The orbit of a planet moving around the Sun
The third law of Kepler is also known as the Law of ______.
If the distance between the sun and the earth is made three times, then attraction between the two will ______
A planet is revolving around the sun in an elliptical orbit as shown in figure. At which point will its K.E. be maximum?

The mass and radius of earth is 'Me' and 'Re' respectively and that of moon is 'Mm' and 'Rm' respectively. The distance between the centre of the earth and that of moon is 'D'. The minimum speed required for a body (mass 'm') to project from a point midway between their centres to escape to infinity is ______.
Both earth and moon are subject to the gravitational force of the sun. As observed from the sun, the orbit of the moon ______.
If the sun and the planets carried huge amounts of opposite charges ______.
- all three of Kepler’s laws would still be valid.
- only the third law will be valid.
- the second law will not change.
- the first law will still be valid.
The centre of mass of an extended body on the surface of the earth and its centre of gravity ______.
- are always at the same point for any size of the body.
- are always at the same point only for spherical bodies.
- can never be at the same point.
- is close to each other for objects, say of sizes less than 100 m.
- both can change if the object is taken deep inside the earth.
Give one example each of central force and non-central force.
What is the direction of areal velocity of the earth around the sun?
Earth’s orbit is an ellipse with eccentricity 0.0167. Thus, earth’s distance from the sun and speed as it moves around the sun varies from day to day. This means that the length of the solar day is not constant through the year. Assume that earth’s spin axis is normal to its orbital plane and find out the length of the shortest and the longest day. A day should be taken from noon to noon. Does this explain variation of length of the day during the year?
The maximum and minimum distances of a comet from the Sun are 1.6 × 1012 m and 8.0 × 1010 m respectively. If the speed of the comet at the nearest point is 6 × 104 ms-1, the speed at the farthest point is ______.
Two planets A and B of equal mass are having their period of revolutions TA and TB such that TA = 2TB. These planets are revolving in the circular orbits of radii rA and rB respectively. Which out of the following would be the correct relationship of their orbits?
What is one practical use of Kepler’s laws?
The time taken by a planet to orbit the Sun depends on ______.
Two identical particles each of mass ‘m’ go round a circle of radius a under the action of their mutual gravitational attraction. The angular speed of each particle will be ______
