Q.1
The potential energy of a satellite, having mass m and rotating at a height of 6.4 χ 106 m from the earth surface, is [ CBSE-PMT 2001]
  • a) -mgRe
  • b) -0.67 mgRe
  • c) -0.5mgRe
  • d) -0.33 mgRe
Q.2
A particle of mass m is thrown upwards from the surface of the earth, with a velocity u. The mass and the radius of the earth are, respectively. M and R. G is gravitational constant and g is acceleration due to gravity on the surface of the earth. The minimum value of u so that the particle does not return back to earth, is [2011M]
  • a)
    ch-7_qn-41choice_img_no1.png
  • b)
    ch-7_qn-41choice_img_no2.png
  • c)
    ch-7_qn-41choice_img_no3.png
  • d)
    ch-7_qn-41choice_img_no4.png
Q.3
Assuming earth to be a sphere of uniform density, what is the value of 'g' in a mine 100 km below the earth's surface? (Given, R=6400 km) [ CBSE-PMT 2001]
  • a) 9.65 m/s2
  • b) 7.65 m/s2
  • c)5.06 m/s2
  • d) 3.10 m/s2
Q.4
The escape velocity from earth is 11.2 km/s. If a body is to be projected in a direction making an angle 45° to the vertical, then the escape velocity is [ CBSE-PMT 1993]
  • a)11.2×2 km/s
  • b) 11.2km/s
  • c)11.2 / √2 km/s
  • d)-(1/2)mv2 km/s
Q.5
The largest and the shortest distance of the earth from the sun are r1 and rIts distance from the sun when it is at perpendicular to the major-axis of the orbit drawn from the sun is [ CBSE-PMT 1988]
  • a) (r1 + r2)/2
  • b) (r1 + r2)/ (r1 - r2)
  • c) 2(r1 × r2)/ (r1 + r2)
  • d) (r1 + r2)/ 3
Q.6
The figure shows elliptical orbit of a planet m about the sun S. The shaded area SCO is twice the shaded area SAB. If t1 is the time for the planet to move from C to D and t2 is the time to move from A to B then : [ CBSE-PMT2009]
ch-7_que_no-45_img_no1.png
  • a) t1=4t2
  • b) t1=2t2
  • c)t1=t2
  • d)t1 > t2
Q.7
If g is the acceleration due to gravity on the earth's surface, the gain in the potential energy of an object of mass m raised from the surface of the earth to a height equal to the radius R of the earth, is [ IIT 1983]
  • a) ½ mg R
  • b) 2 mg R
  • c)mg R
  • d)¼ mg R
Q.8
If the distance between the earth and the sun were half its present value, the number of days in a year would have been [ IIT 1996]
  • a) 64.5
  • b) 129
  • c) 182.5
  • d) 730
Q.9
An artificial satellite moving in a circular orbit around the Earth has a total ( kinetic + potential) Energy EIts potential energy is [ IIT 1997]
  • a)- E0
  • b) 1.5 E0
  • c)2E0
  • d)E0
Q.10
A go-stationary satellite orbits around the earth in a circular orbit of radius 36,000km. Then, the time period of a spy satellite orbiting a few hundred km above the earth's surface ( Radius of earth=6,400 km) will approximately be [ IIT 2002]
  • a) 0.5 hr
  • b) 1 hr
  • c)2 hr
  • d)4 hr
Q.11
A binary star system consists of two stars A and B which have time period TA and TB, radius RA And RB and mass MA and MB. Then [ IIT 2006]
  • a) if TA > TB and RA > RB
    ch-7_qn-51choice_img_no4.png
  • b) if TA > TB and MA > MB
  • c)TA=TB
  • d)
Q.12
A simple pendulum is oscillating without damping. When the displacement of the bob is less than maximum, its acceleration vector a is correctly shown in [ IIT 2002]
  • a)
    ch-7_qn-52choice_img_no1.png
  • b)
    ch-7_qn-52choice_img_no2.png
  • c)
    ch-7_qn-52choice_img_no3.png
  • d)
    ch-7_qn-52choice_img_no4.png
Q.13
The kinetic energy needed to project body of mass m from the earth surface ( radius R) to infinity is [AIEEE 2002]
  • a) mgR / 2
  • b) 2 mg R
  • c)mg R
  • d)mg R/4
Q.14
If suddenly the gravitational force of attraction between earth and a satellite revolving around it becomes zero, then the satellite will [ AIEEE 2002]
  • a)continue to move in its orbit with same velocity
  • b) move tangentially to the original orbit in the same velocity
  • c) become stationary in its orbit
  • d)move towards the earth
Q.15
Energy required to move a body of mass m from an orbit of radius 2R to 3R is [ AIEEE 2002]
  • a) GMm/ 12R2
  • b) GMm / 3R2
  • c)GMm / 8R
  • d)GMm / 6R
Q.16
The escape velocity of a body depends upon mass as [ AIEEE 2002]
  • a) m0
  • b) m1
  • c) m2
  • d) m3
Q.17
The time period of a satellite of earth is 5 hours. If the separation between the earth and the satellite is increased to 4 times the previous value, the new time period will become [ AIEEE 2003]
  • a)10 hrs
  • b) 80 hrs
  • c)40 hrs
  • d)20 hrs
Q.18
Two spherical bodies of mass M and 5M and radii R and 2R respectively are released in free space with initial separation between their centers equal to 12R. If they attract each other due to gravitational force only, then the distance covered by the smaller body just before collision is [ AIEEE 2003]
  • a) 2.5R
  • b) 4.5R
  • c)7.5R
  • d)1.5R
Q.19
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]
  • a) 11√2 km/s
  • b) 22 km/s
  • c)11 km/s
  • d)(11/√2) km/s
Q.20
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]
  • a) gR2 /(R+x)
  • b) gar / (R-x)
  • c) g
  • d) [gR2 /(R+x)]1/2
Q.21
The time period of an earth satellite in circular orbit is independent of [ AIEEE 2004]
  • a)both the mass and radius of the orbit
  • b) radius of orbit
  • c)the mass of the satellite
  • d)neither the mass of the satellite nor the radius of its orbit
Q.22
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]
  • a) ¼ mgR
  • b) ½ mgR
  • c)2mg R
  • d)mg R
Q.23
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]
  • a) Rn
    ch-7_qn-63choice_img_no2.png
  • b)
    ch-7_qn-63choice_img_no3.png
  • c)
    ch-7_qn-63choice_img_no4.png
  • d)
Q.24
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]
  • a) d=3h/2
  • b) d=h/2
  • c) d=h
  • d) d=2h
Q.25
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]
  • a) 3.33 × 10-10 J
  • b) 13.34 × 10-10 J
  • c)6.67× 10-10 J
  • d)6.67× 10-9 J
Q.26
Average density of the earth [ AIEEE 2005]
  • a) is a complex function of g
  • b) does not depend on g
  • c)is inversely proportional to g
  • d)is directly proportional to g
Q.27
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]
  • a) 1.1 km/s
  • b) 11 km/s
  • c)110km/s
  • d)0.11 km/s
Q.28
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]
  • a) R / √2
  • b) R/ 2
  • c) √2 R
  • d) 2R
Q.29
If the earth is at one fourth of its present distance from the sun, the duration of the year will be [ EAMCET 1987]
  • a)half the present year
  • b) one-eight the present year
  • c)one-fourth the present year
  • d)one sixth the present year
Q.30
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]
  • a) 41.4%
  • b) 82.8%
  • c)100%
  • d)none of the above
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