Q.1.
The escape velocity for a body projected vertically upwards from the surface of earth is 11 km/s. If the body is projected at an angle of 45° with the vertical, the escape velocity will be [ AIEEE 2003]
-
0%
a) 11√2 km/s
-
23%
b) 22 km/s
-
54%
c)11 km/s
-
23%
d)(11/√2) km/s
Q.2.
A satellite of mass m revolves around the earth of radius R at a height x from its surface. If g is the acceleration due to gravity on the surface of the earth, the orbital speed of the satellite is [ AIEEE 2004]
-
11%
a) gR2 /(R+x)
-
44%
b) gar / (R-x)
-
11%
c) g
-
33%
d) [gR2 /(R+x)]1/2
Explanation
Q.3.
The time period of an earth satellite in circular orbit is independent of [ AIEEE 2004]
-
44%
a)both the mass and radius of the orbit
-
22%
b) radius of orbit
-
33%
c)the mass of the satellite
-
0%
d)neither the mass of the satellite nor the radius of its orbit
Q.4.
If 'g' is the acceleration due to gravity on the earth's surface, the gain in the potential energy of an masses ' m' raised from the surface of the earth to height equal to the radius 'R' around the earth is [ AIEEE 2004]
-
33%
a) ¼ mgR
-
44%
b) ½ mgR
-
22%
c)2mg R
-
0%
d)mg R
Q.5.
Suppose the gravitational force varies inversely as the nth power of distance. Then the time period of planet in circular orbit of radius 'R' around the sun will be proportional to [ AIEEE 2004]
-
22%
a) Rn
-
33%
b)
-
11%
c)
-
33%
d)
Explanation
Q.6.
The change in the value of 'g' at height 'h' above the surface of the earth is same as at a depth 'd' below the surface of earth. When both 'd' and 'h' are much smaller than the radius of earth, then which one of the following is correct [ AIEEE 2005]
-
14%
a) d=3h/2
-
43%
b) d=h/2
-
29%
c) d=h
-
14%
d) d=2h
Explanation
Q.7.
A particle of mass 10g is kept on the surface of a uniform sphere of mass 100kg and radius 10cm. Find the work to be done against the gravitational force between them to take the particle far away from the sphere ( G=6.67 × 10-11 Nm2 / kg2) [ AIEEE 2005]
-
0%
a) 3.33 × 10-10 J
-
0%
b) 13.34 × 10-10 J
-
60%
c)6.67× 10-10 J
-
40%
d)6.67× 10-9 J
Q.8.
Average density of the earth [ AIEEE 2005]
-
0%
a) is a complex function of g
-
12%
b) does not depend on g
-
12%
c)is inversely proportional to g
-
75%
d)is directly proportional to g
Explanation
Q.9.
A planet in a distant solar system is 10 times more massive than earth and its radius is 10 times smaller. Given that the escape velocity from the earth is 11 km/s, the escape velocity from the surface of the planet would be [ AIEEE 2008]
-
0%
a) 1.1 km/s
-
57%
b) 11 km/s
-
43%
c)110km/s
-
0%
d)0.11 km/s
Explanation
Q.10.
The height at which the acceleration due to gravity becomes g/9 ( where g=the acceleration due to gravity on the surface of the earth) in terms of R, the radius of the earth is [ AIEEE 2009]
-
29%
a) R / √2
-
29%
b) R/ 2
-
14%
c) √2 R
-
29%
d) 2R
Explanation
Q.11.
If the earth is at one fourth of its present distance from the sun, the duration of the year will be [ EAMCET 1987]
-
0%
a)half the present year
-
0%
b) one-eight the present year
-
43%
c)one-fourth the present year
-
57%
d)one sixth the present year
Explanation
Q.12.
A satellite is moving round the earth with velocity v. To make the satellite escape, the minimum percentage increase in its velocity is nearly [ MPPET 1994]
-
12%
a) 41.4%
-
12%
b) 82.8%
-
50%
c)100%
-
25%
d)none of the above
Q.13.
The gravitational potential energy of a rocket of mass 100kg at a distance 109 m from earth surface is 4 × 107 joule. The weight of the rocket in Newton's at distance 109 m from earth is ( Re=6400 km)
-
0%
a) 8 ×10-2 N
-
14%
b) 8 × 10-3 N
-
71%
c)4 × 10-3 N
-
14%
d)4 × 10-2N
Explanation
Q.14.
A missile is launched with a velocity less than the escape velocity. The sum of its kinetic and potential energy is [ MNR 1986]
-
29%
a) positive
-
43%
b) negative
-
14%
c) zero
-
14%
d) may be positive or negative depending upon its initial velocity
Q.15.
Consider a satellite going round the earth in a circular orbit. Which of the following statements is wrong?
-
29%
a)It is freely falling body
-
29%
b) It is acted upon by a force directed away from the center of the earth which counter-balances the gravitational pull
-
14%
c)It is moving with constant speed
-
29%
d)Its angular momentum remains constant
Q.16.
Imagine a light planet revolving around a very massive star in circular orbit of radius R with a period of revolution T. If the gravitational force of attraction between planet and star is proportional t R-5/2, then T2 is proportional to ..[ IIT 1989]
-
33%
a) R3
-
17%
b) R7/2
-
33%
c)R5/2
-
17%
d)R3/2
Explanation
Q.17.
A spherical planet far out in space has a mass Mo and diameter Do. A particle of mass m falling freely near the surface of this planet will experience acceleration due to gravity which is equal to [ MPPMT 1987]
-
33%
a) GMo / D20
-
17%
b) 4m GMo / D20
-
50%
c) 4GMo / D20
-
0%
d) GmMo / D20
Q.18.
Which of the following represents the Newton's law of universal gravitation correctly
-
33%
a)
-
17%
b)
-
33%
c)
-
17%
d)
Q.19.
The gravitational potential at any point distant r from a point mass m is work done in moving a unit mass from
-
17%
a)the point of interest to infinity
-
33%
b) from infinity to the point of interest
-
33%
c)from the position of point mass m to the point of interest
-
17%
d)from infinity to the position of point mass m
Q.20.
If earth ware to cease rotating about its own axis, the increase in the value of g is C.G.S system at equator is nearly
-
40%
a) 3.36 cm/s2
-
40%
b) 6.72 cm/s2
-
0%
c)1.68 cm/s2
-
20%
d)0.84 cm/s2
Q.21.
An astronaut orbiting the earth in a circular orbit 120km above the surface of earth, gently drops a spoon from the spaceship. The spoon will [Raj-PMT 1996]
-
17%
a) fall vertically down to the earth
-
33%
b) move towards the moon
-
33%
c)will move along with the spaceship
-
17%
d)will move in an irregular way and then fall down to earth
Q.22.
The earth revolves round the sun in an elliptical orbit. Its speed is
-
0%
a) goes on decreasing continuously
-
60%
b) greatest when it is closest to the sun
-
20%
c) greatest when it is farthest from the sun
-
20%
d) constant at all the points on the orbit
Q.23.
Two satellites A and B go around a planet P in circular orbit having radii 4R and R respectively if the speed of the satellite a is 3V, the speed of the satellite B will be [ MNR 1991]
-
0%
a)12V
-
80%
b) 6V
-
20%
c)(4/3)V
-
0%
d)(3/2)V
Q.24.
In a gravitational field, at a point where the gravitational potential is zero
-
0%
a) the gravitational field is necessarily zero
-
40%
b) the gravitational field is not necessarily zero
-
40%
c)nothing can be said definitely about gravitational field
-
20%
d)none of the above
Q.25.
A satellite is orbiting around the earth in the equatorial plane rotating from west to east as the earth does. If ωe is angular velocity of earth and ωs is angular velocity of satellite, then the satellite will appear at the same location after a time t=
-
80%
a)
-
0%
b)
-
0%
c)
-
20%
d)
Q.26.
A solid sphere of uniform density and mass M has a radius of 4m. Its center is at the origin of coordinate system. Two sphere of radii 1 m are taken out so that their centers are at P(0, -2, 0) and Q(0, 2, 0) respectively. This leaves two spherical cavities. What is the gravitational field at the center of each cavity
-
40%
a) (31/1024) GM
-
20%
b) GM/ 1024
-
20%
c) 31 GM
-
20%
d) GM
Explanation
Q.27.
The tail of the Comet Halley is directed away from sun due to the fact that..[ CPMT 1988]
-
20%
a)As the comet rotates around the sub the lighter mass of the comet is pushed away due to centrifugal force only
-
40%
b) as the comet rotates, the lighter mass of the comet is attracted by some star situated in direction of the tail
-
40%
c)the radiation emitted by the sun exerts a radiant pressure on the comet throwing its tail away from sun
-
0%
d)the tail of the comet always exists in the same orientation
Q.28.
Kepler's second law states that the straight line joining the planet to the sun sweeps out equal areas in equal times. This statement is equivalent to saying that
-
60%
a) total acceleration is zero
-
20%
b) transverse acceleration is zero
-
0%
c)tangential acceleration is zero
-
20%
d)radial acceleration is zero
Q.29.
The point masses m1 and m2 are initially at rest and at infinite distance apart. They start moving towards one another under their mutual gravitation field. There relative speed when they are at distance d apart is ;
-
0%
a)
-
100%
b)
-
0%
c)
-
0%
d)
Explanation
Q.30.
A planet moves around the sun. At a point P it is closest from the sun at a distance d1 and has a speed vAt another point Q, when it is farthest fron the sun at a distance d2, its speed will be [ MPPMT 1987]
-
0%
a) d12v1 / d22
-
50%
b) d2v1 / d1
-
33%
c) d1v1 / d2
-
17%
d) d22v1 / d12