Q.1
What will be the formula of the mass in terms of g, R and G (R=radius of earth) [ CBSE-PMT 1996]
  • a)g2(R/G)
  • b) G (R2/g)
  • c)G (R/g)
  • d) g(R2/G)
Q.2
The escape velocity from the surface of the earth is ve.The escape velocity from the surface of a planet whose mass and radius are three times those of the earth, will be [ CBSE-PMT 1995]
  • a) ve
  • b) 3ve
  • c)9ve
  • d)(1/3)ve
Q.3
The acceleration due to gravity on the planet A is 9 times the acceleration due to gravity on planet B. A man jumps to a height of 2m on the surface of A. What is the height of jump by the same person on the planet B? [ CBSE-PMT 2003]
  • a)(2/3)m
  • b) (2/9) m
  • c)18m
  • d)6m
Q.4
A planet moving along an elliptical orbit is closest to the sun at a distance r1 and farthest away at a distance of rIf v1 and v2 are the linear velocities at these points respectively, then the ratio is [2011]
  • a) (r1/r2)2
  • b) r2/r1
  • c) (r2/r1)2
  • d) r1/r2
Q.5
Two satellites of earth, S1 and S2 , are moving in the same orbit. The mass of S1 is four times the mass of S2 Which one of the following statements is true? [2007]
  • a)The potential energies of earth satellites in the two cases are equal.
  • b) S1 and S2, are moving with the same speed.
  • c)The kinetic energies of the two satellites are equal.
  • d)The time period of S1 is four times that of S2
Q.6
The Earth is assumed to be a sphere of radius R. A platform is arranged at a height R from the surface of the Earth. The escape velocity of a body from this platform is fv, where v is its escape velocity from the surface of the Earth. The value of f is - [ CBSE-PMT 2006]
  • a) 1/√2
  • b) 1/3
  • c)1/2
  • d)√2
Q.7
The density of a newly discovered planet is twice that of earth. The acceleration due to gravity at the surface of the planet is equal to that at the surface of the earth. If the radius of the earth is R. the radius of the planet would be [ CBSE-PMT 2004]
  • a) R / 2
  • b) 2R
  • c)4R
  • d)R/4
Q.8
Imagine a new planet having the same density as that of earth but it is 3 times bigger than the earth in size. If the acceleration due to gravity on the surface of earth is g and that on the surface of the new planet is g', then [ CBSE-PMT 2005]
  • a) g'=g/9
  • b) g'=27g
  • c) g'=9g
  • d) g'=3g
Q.9
For a satellite moving in an orbit around the earth, the ratio of kinetic energy to potential energy is [ CBSE-PMT 2005]
  • a) 1/2
  • b) 1/√2
  • c)2
  • d)√2
Q.10
The period of revolution of planet A around the Sun is 8 times that of B. The distance of A from the Sun is how many times greater than that of B from the Sun? [1997]
  • a) 2
  • b) 3
  • c)4
  • d)5
Q.11
The mean radius of earth is R, its angular speed on its own axis is ω and the acceleration due to gravity at earth's surface is g. What will be the radius of the orbit of a geostationary satellite ?[ CBSE-PMT 1992]
  • a)(R2g/ω2)1/3
  • b)(Rg/ω2)1/3
  • c)(R2 ω2/g)1/3
  • d)(R2 g/ ω)1/3
Q.12
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.13
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.14
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.15
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.16
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.17
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.18
If radius of the earth were to shrink by one percent, its mass remaining the same, the acceleration due to gravity on the earth's surface would [ IIT 1981]
  • a) decrease
  • b) remain unchanged
  • c)increase
  • d)be zero
Q.19
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.20
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.21
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.22
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.23
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.24
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.25
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.26
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.27
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.28
The escape velocity of a body depends upon mass as [ AIEEE 2002]
  • a) m0
  • b) m1
  • c) m2
  • d) m3
Q.29
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.30
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
0 h : 0 m : 1 s