Physics CSIR Study material Part -1 - Gravitation


A thief stole a box with valuable article of weight ‘W’ and jumped down a wall of height h. Before he reach the ground he experienced a load of

(a) zero

(b) W / 2

(c) W

(d) 2 W


The acceleration due to gravity g and mean density of the earth r are related by which of the following relation? Where g is gravitational constant and R is radius of the earth

(a) r =

(b) r =

(c) r =

(d) r =


When the planet comes nearer the sun moves

(a) fast

(b) slow

(c) constant at every point

(d) none of the above


Kepler’s second law regarding constancy of arial velocity of a planet is a consequence of the law of conservation of

(a) energy

(b) angular momentum

(c) linear momentum

(d) none of these


The period of geostationary artificial satellite is

(a) 24 hours

(b) 6 hours

(c) 12 hours

(d) 48 hours


A geostationary satellite is orbiting the earth at a height of 6R above the surface of the earth, R being the radius of the earth. The time period of another satellite at a height of 2.5 R from the surface of earth is

(a) 6 hr

(b) 6 hr

(c) 5 hr

(d) 10 hr


The distance of Neptune and Saturn from the sun are nearly 1013 m and 1012 m respectively. Assuming that they move in circular orbits, their periodic times would be in the ratio of

(a) 10

(b) 100

(c) 10

(d) 1000


A satellite is orbiting close to the surface of the earth, then its speed is


(b) Rg




If the gravitational force between two objects were proportional to 1/R (and not as 1/R2) where R is separation between them, then a particle in circular orbit under such a force would have its orbital speed v proportional to


(b) R0

(c) R1



Imagine a light planet revolving around a very massive star in a circular orbit of radius R with a period of revolution T. If the gravitational force of attraction between the planet and the star is proportional to then

(a) T2 a R2

(b) T2 a

(c) T2 a

(d) T2 a R3

1. Ans.: (a)
2. Ans.: (c)
3.Ans.: (a)
4. Ans.: (b)
5. Ans.: (a)
6. Ans.: (a)
7. Ans.: (c)
8. Ans.: (c)
9. Ans.: (b)
10. Ans.: (b)