QUES – Escape velocity from the earth 11.2 km/sec . Another planet of same mass has radius ¼ times that of earth . What is the escape velocity from this planet ?
11.2 km/sec
44.8 km/sec
22.4 km/sec
5.6 km/sec
• QUES -2 – A body attends the height equal to the radius of the earth when projected from earth surface . The velocity of the body with which it was projected is :
(A)
(B)
(C)
(D)
QUES -3 – An earth satellite is moving in a circular orbit with a uniform speed v , if the gravitational force of the earth suddenly disappear , the satellite will
Vanish into outer space
Continue to move with velocity v in original orbit
Fall down with increasing velocity
Fly off tangentially from the orbit with velocity v
QUES -4 – the maximum and minimum distance of a comet from the sun are 8 X 10 2 m and 1.6 X 1012 m representing . If its velocity when it is nearest to the sun is 60 m/sec then what will be its velocity in m/s when it is farthest ?
12
60
(C) 112
(D) 6
QUES -5 – the gravitational potential energy of a body at a distance r from the center of the earth is u . The force at a point :
u/r2
u/r
Ur
ur2
QUES -6- if the spinning speed of earth is increased , then the weight of the body at the equator
QUES -7 – when the radius of earth reduced by 1% without changing the mass , then the acceleration due to gravity will
Increase by 2 %
Decreases by 1.5 %
Increases by 1 %
Decreases by 1 %
QUES -8 – a particle falls from infity the earth . Its velocity on reaching the earth surface is
2Rg
Rg (C) (D)
QUES -9 – weight of a body mass M decreased by 1 % when it is raised to height h above the earth surface . If the body is taken to the depth h in a mine , then in its weight will
Decrease by 0.5 %
Decrease by 2 %
Increase by 0.5 %
Increase by 1 %
QUES -10 – the escape velocity from the earth 11.2 km/sec . The mass of another planet is 100 times of mass of earth and its radius is 4 times the radius of earth . The velocity of the planet is :
56.0 km/sec
280 km/sec
112 km/sec
11.2 km/sec
QUES -11 – acceleration due to gravity of earth surface is ‘g’ ms-2 find the effective value of acceleration due to gravity at a height of 32 km from sea level : (Re = 6400 km )
(A) 0.5 g ms-2
(B) 0.99 g ms-2
(C) 1.01 g ms -2
(D) 0.90 g ms-2
QUES -12 –near the earth surface time period of a satellite is 1.4 hrs. find its time period if its is at the distance ‘4R’ from the center of earth :
(A) 32 hrs. (B) ( 1/8 2)
8 2
16 hrs .
QUES -13 – the mass of moon is 1% of mass of the earth . The ratio of gravitational pill of earth on moon to that of moon on earth will be :
(A) 1:1 (B) 1:10 (C) 1:100
(D) 2:1
QUES -14 – a palnet revolve around the sun in an elliptical orbit . If vp and va are the velocities of the planet at the perigee and apogee respectively , then the eccentricity of the elliptical orbit is given by :
(A)^{π£}π
π£π
(B)π£π −π£π
π£π+π£π
(C)π£π+π£π
π£π−π£π
(D)π£π −π£π
π£π+π£π
QUES -15 –a communication of satellite of earth which takes 24 hrs . To complete one circular orbit eventually has to be replaced by another satellite of double mass . If the new satellite also ha s on orbital time period of 24 hrs , then what is the ratio of the radiusof the new orbit to original orbit ?
(A) 1:1
(B) 2:1
(C) :1
(D) 1:2
QUES -16 –when you move from equator to pole , the value of acceleration due to gravity (g) ;
Increase
Decrease
Remains the same
First increase then decrease
QUES -17 – imagine a new planet having the same density as that of earth but it is 3 times bigger than the size . If the acceleration due to gravity on the surface of earth is g and that on the surface of the new planet :
g’=3g
g’=g/9
g’=9g
G’=27g
QUES -18 –escape velocity for a projectile at earth surface is ve . Abody is projected from eart’s surface with velocity 2 v e . The velocity of the body when it is at infinite distance from the center of the earth is :
Ve
2ve
2 ve
3 ve
QUES -19 – for a satellite moving in an orbit around the earth , the ratio of kinetic energy to potential energy is :
2
½
2
(D) 1/ 2
QUES -20 – if earth revolves around the sun in an orbit of double radius of its present radius . Then the year on earth will be of –
(A) 365/4 days
(B) 365 x 2 2 πππ¦π
365/2 days
365 x4 days
QUES – 21- mars has diameter approximately 0.5 of that of earth . And mass of 0.1 of that earth . The surface gravitational field strength on mars as compared of that on earth is greater by a factor of –
(A) 0.1
(B) 0.2
(C) 2.0
(D) 0.4
QUES -22 –the change in the value of g at a height ‘h’ above the surface of the earth is same as that a depth ‘d’ . If ‘d’ and ‘h’ are much smaller than the radius of earth , then which one of the following is correct ?
d=h
D=2h
D=3h/2
D=h/2
QUES -23 – two satellite of earth S1 and S2 are moving in the same orbit . The mass of S1 is four times the mass S2 , which one of the following statement is true /
The kinetic energies of the two satellite are equal
The times period of S1 is four times that of S2
The potential energies of earth and satellite in the two cases are equal
S1 and S 2 are moving with the same speed
QUES -24 –the angular speed of earth is radian per sec , so that bodies on equator may appear weightless is :
(A) 1.25 x 10-3
(B) 1.56 x 10 +-3
(C) 1.25 x 10 -3
(D) 1.56
QUES -25 – a body weight W newton the surface of the earth . Its weight at a height equal to half the radius of earth will be :
W/2
2W/3
4W/9
W/4
QUES -26 – the radii of circular orbit two satellite A and B of the earth are 4R and R respectively, if the speed of satellite A and 3V , then the speed of satellite B will be ;
3V/2
3V/4
6V
12V
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QUES -27 – A particle have mass M is situated at the center of a spherical shell of same mass and radius a the gravitational potential at a point situated at a/2 distance from the center , will be :
-4GM/a
-3GM/a
-2GM/a
-GM/a
QUES -28 – The additional kinetic energy to be provided to a satellite of mass m revolving around a planet of mass M , to transfer it form a circular orbit of radius R1 to another of radius R2 (R2 >R1 ) is :
1 1
(A) GmM(π 1 -π 2)
1 1
(B) 2GmM(π 1 -π 2)
1 1
(C) 1/2GmM(π 1 -π 2)
1 1
(D) GmM(π 2 -π 2)
1 2
QUES -29 – A planet moving along a elliptical orbit is closet to the sun at a distance t1 and farthest away at a distance of r2 . If v1 and v2 are the linear velocities at these points respectively , then the ratio v1 /v2 is :-
(A) (r1 /r2 )2
(B) r1 /r2 (C) (r2 /r1 )2
(D) r1 /r2
QUES -30 – a spherical planet has mass Mp and diameter Dp A particle of mass m falling freely near the surface of thie surface of this planet will experience an acceleration due to gravity equa;l to :
GMP /DP2
4GMP /DP2
4GMP m/DP2
GMP m/DP2
QUES -31 – A geostationary satellite is orbiting the earth at a height of 5R above that surface of earth , R being the radius of the earth , R being the radius of the earth . The time period of another satellite in hour at a height of 2R from the surface of the earth is :
(A) 6 2
(B) 6/ 2
5
10
QUES -32 –the height at which the weight of a body becomes 1/16th , its weight on the surface of earth (radius R) is :
3R
4R
5R
15R
QUES -33 – A particle is thrown with escape velocity ve from the surface of earth . Calculate its velocity at height 3R:
9.25Km/s
-5.6 Km/s
11.2 Km/s
4.3 Km/s
QUES – 34-newton’s law of gravitation is :
Is not applicable out side the solar system
Is used to govern the motion of satellite only
Control the rotational motion of satellite and planet
Control the rotational motion of electron in atoms
QUES -35 – acceleration due to gravity at the center of earth is :
G
g/2
Zero
Infinite
QUES -36 – if the distance between centers of earth and moon D and mass of earth is 81 times that of moon . At what distance from the center of earth gravitational field will be zero :
D/2
2D/3
4D/5
(D) 9D/10
QUES -37 – A particle falls on earth(i) from infinity , (ii) from a height 10 times of radius of earth . The ratio of the velocities gained on
reaching at the earth’s surface is :
(A) 11: 10
(B) 10: 11
(C) 10:11
(D) 11:10
QUES – 38 – the binding energy of moon is :
(A)πΊππ ππ /πππ (B)πΊππMm /rem (C)πΊππ Mm /rem
(D) - πΊππMm /rem
QUES -39 – the average radii of a orbit mercury and earth around the sun are 6 x 10 7 km and 1.5 x 108 km respectively . The ratio of their orbital speed will be :
(A) 5: 2
(B) 2: 5 (C) 2.5 :1 (D) 1:25
QUES -40 – A body is drop by a satellite in its geo – stationary orbit :
It will burn on entering in to the atmosphere
it will remain in the same place with respect to earth