Total Questions:50 Total Time: 75 Min
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Question:A body weighs 700 gm wt on the surface of the earth. How much will it weigh on the surface of a planet whose mass is \(\frac{1}{7}\) and radius is half that of the earth
200 gm wt
400 gm wt
50 gm wt
300 gm wt
Question:In order to find time, the astronaut orbiting in an earth satellite should use
A pendulum clock
A watch having main spring to keep it going
Either a pendulum clock or a watch
Neither a pendulum clock nor a watch
Question:A spherical planet far out in space has a mass \({M_0}\) and diameter \({D_0}\). A particle of mass m falling freely near the surface of this planet will experience an acceleration due to gravity which is equal to
\(G{M_0}/D_0^2\)
\(4mG{M_0}/D_0^2\)
\(4G{M_0}/D_0^2\)
\(Gm{M_0}/D_0^2\)
Question:The value of g on the earth's surface is \(980\,cm/{\sec ^2}\). Its value at a height of 64 km from the earth's surface is
\(960.40\,cm/{\sec ^2}\)
\(984.90\,cm/{\sec ^2}\)
\(982.45\,cm/{\sec ^2}\)
\(977.55\,cm/{\sec ^2}\)
Question:Choose the correct statement from the following :Weightlessness of an astronaut moving in a satellite is a situation of
Zero g
No gravity
Zero mass
Free fall
Question:If the earth rotates faster than its present speed, the weight of an object will
Increase at the equator but remain unchanged at the poles
Decrease at the equator but remain unchanged at the poles
Remain unchanged at the equator but decrease at the poles
Remain unchanged at the equator but increase at the poles
Question:If the radius of the earth shrinks by 1.5% (mass remaining same), then the value of acceleration due to gravity changes by
1%
2%
3%
4%
Question:If radius of the earth contracts 2% and its mass remains the same, then weight of the body at the earth surface
Will decrease
Will increase
Will remain the same
None of these
Question:If mass of a body is M on the earth surface, then the mass of the same body on the moon surface is
M/6
Zero
M
Question:The angular speed of earth, so that the object on equator may appear weightless, is \((g = 10\,m/{s^2}\), radius of earth 6400 km)
\(1.25 \times {10^{ - 3}}rad/sec\)
\(1.56 \times {10^{ - 3}}rad/sec\)
\(1.25 \times {10^{ - 1}}rad/sec\)
1.56 rad/sec
Question:At what distance from the centre of the earth, the value of acceleration due to gravity g will be half that on the surface (R = radius of earth)
2 R
R
1.414 R
0.414 R
Question:The depth at which the effective value of acceleration due to gravity is \(\frac{g}{4}\) is
\(\frac{{3R}}{4}\)
\(11.2 \times {10^2}\,km{s^{ - 1}}\)
\(\frac{R}{4}\)
Question:Weight of a body of mass m decreases by 1% when it is raised to height h above the earth’s surface. If the body is taken to a depth h in a mine, change in its weight is
2% decrease
0.5% decrease
1% increase
0.5% increase
Question:If both the mass and the radius of the earth decrease by 1%, the value of the acceleration due to gravity will
Decrease by 1%
Increase by 1%
Increase by 2%
Remain unchanged
Question:There are two bodies of masses 100 kg and 10000 kg separated by a distance 1 m. At what distance from the smaller body, the intensity of gravitational field will be zero
\(\frac{1}{9}m\)
\(\frac{1}{{10}}m\)
\(\frac{1}{{11}}m\)
\(\frac{{10}}{{11}}m\)
Question:What is the intensity of gravitational field of the centre of a spherical shell
\(Gm/{r^2}\)
g
Question:The gravitational potential energy of a body of mass ‘m’ at the earth’s surface \( - mg{R_e}\). Its gravitational potential energy at a height \({R_e}\) from the earth’s surface will be (Here \({R_e}\) is the radius of the earth)
\( - 2\,mg{R_e}\)
\(2\,mg{R_e}\)
\(\frac{1}{2}mg{R_e}\)
\( - \frac{1}{2}mg{R_e}\)
Question:The escape velocity from the earth is about 11 km/second. The escape velocity from a planet having twice the radius and the same mean density as the earth, is
22 km/sec
11 km/sec
5.5 km/sec
15.5 km/sec
Question:A missile is launched with a velocity less than the escape velocity. The sum of its kinetic and potential energy is
Positive
Negative
May be positive or negative depending upon its initial velocity
Question:If g is the acceleration due to gravity at the earth's surface and r is the radius of the earth, the escape velocity for the body to escape out of earth's gravitational field is
gr
\(\sqrt {2gr} \)
\(g/r\)
\(r/g\)
Question:Given mass of the moon is 1/81 of the mass of the earth and corresponding radius is 1/4 of the earth. If escape velocity on the earth surface is 11.2 km/s, the value of same on the surface of the moon is
0.14 km/s
0.5 km/s
2.5 km/s
5 km/s
Question:The angular velocity of rotation of star (of mass M and radius R) at which the matter start to escape from its equator will be
\(\sqrt {\frac{{2G{M^2}}}{R}} \)
\(\sqrt {\frac{{2GM}}{g}} \)
\(\sqrt {\frac{{2GM}}{{{R^3}}}} \)
\(\sqrt {\frac{{2GR}}{M}} \)
Question:The escape velocity for the earth is \({v_e}\). The escape velocity for a planet whose radius is four times and density is nine times that of the earth, is
\(36\,{v_e}\)
\(12\,{v_e}\)
\(6\,{v_e}\)
\(20\,{v_e}\)
Question: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 45o with the vertical, the escape velocity will be
\(\frac{{11}}{{\sqrt 2 }}km/s\)
\(11\sqrt 2 \,km/s\)
22 km/s
11 km/s
Question:If V, R and g denote respectively the escape velocity from the surface of the earth radius of the earth, and acceleration due to gravity, then the correct equation is
\(V = \sqrt {gR} \)
\(V = \sqrt {\frac{4}{3}g{R^3}} \)
\(V = R\sqrt g \)
\(V = \sqrt {2gR} \)
Question:Two planets move around the sun. The periodic times and the mean radii of the orbits are \({T_1},\,{T_2}\) and \({r_1},\,{r_2}\) respectively. The ratio \({T_1}/{T_2}\) is equal to
\({({r_1}/{r_2})^{1/2}}\)
\({r_1}/{r_2}\)
\({({r_1}/{r_2})^2}\)
\({({r_1}/{r_2})^{3/2}}\)
Question:Kepler's second law regarding constancy of aerial velocity of a planet is a consequence of the law of conservation of
Energy
Angular momentum
Linear momentum
Question:The maximum and minimum distances of a comet from the sun are \(8 \times {10^{12}}\,m\) and \(1.6 \times {10^{12}}\,m\). If its velocity when nearest to the sun is 60 m/s, what will be its velocity in m/s when it is farthest
12
60
112
6
Question:A body revolved around the sun 27 times faster then the earth what is the ratio of their radii
3-Jan
9-Jan
27-Jan
4-Jan
Question:The period of moon’s rotation around the earth is nearly 29 days. If moon’s mass were 2 fold, its present value and all other things remained unchanged, the period of moon’s rotation would be nearly
\(29\sqrt 2 \)days
\(29/\sqrt 2 \) days
29 × 2 days
29 days
Question:What does not change in the field of central force
Potential energy
Kinetic energy
Question:The eccentricity of earth's orbit is 0.0167. The ratio of its maximum speed in its orbit to its minimum speed is
2.507
1.033
8.324
1
Question:The mass of a planet that has a moon whose time period and orbital radius are T and R respectively can be written as
\(4{\pi ^2}{R^3}{G^{ - 1}}{T^{ - 2}}\)
\(8{\pi ^2}{R^3}{G^{ - 1}}{T^{ - 2}}\)
\(12{\pi ^2}{R^3}{G^{ - 1}}{T^{ - 2}}\)
\(16{\pi ^2}{R^3}{G^{ - 1}}{T^{ - 2}}\)
Question:The period of a satellite in a circular orbit around a planet is independent of
The mass of the planet
The radius of the planet
The mass of the satellite
All the three parameters ,
1 and 2
Question:If a satellite is orbiting the earth very close to its surface, then the orbital velocity mainly depends on
The mass of the satellite only
The radius of the earth only
The orbital radius only
The mass of the earth only
Question:The relay satellite transmits the T.V. programme continuously from one part of the world to another because its
Period is greater than the period of rotation of the earth
Period is less than the period of rotation of the earth about its axis
Period has no relation with the period of the earth about its axis
Period is equal to the period of rotation of the earth about its axis
Mass is less than the mass of the earth
Question:Two identical satellites are at R and 7R away from earth surface, the wrong statement is (R = Radius of earth)
Ratio of total energy will be 4
Ratio of kinetic energies will be 4
Ratio of potential energies will be 4
Ratio of total energy will be 4 but ratio of potential and kinetic energies will be 2
Question:For a satellite escape velocity is 11 km/s. If the satellite is launched at an angle of \({\rm{6}}0^\circ \) with the vertical, then escape velocity will be
\(11\sqrt 3 \) km/s
\(\frac{{11}}{{\sqrt 3 }}\) km/s
33 km/s
Question:Given radius of Earth ‘R’ and length of a day ‘T’ the height of a geostationary satellite is [G–Gravitational Constant, M–Mass of Earth]
\({\left( {\frac{{4{\pi ^2}GM}}{{{T^2}}}} \right)^{1/3}}\)
\({\left( {\frac{{4\pi GM}}{{{R^2}}}} \right)^{1/3}} - R\)
\({\left( {\frac{{GM{T^2}}}{{4{\pi ^2}}}} \right)^{1/3}} - R\)
\({\left( {\frac{{GM{T^2}}}{{4{\pi ^2}}}} \right)^{1/3}} + R\)
Question:A geo-stationary satellite is orbiting the earth at a height of 6 R above the surface of earth, R being the radius of earth. The time period of another satellite at a height of 2.5 R from the surface of earth is
10 hr
\((6/\sqrt 2 )\,hr\)
6 hr
\(6\sqrt 2 \,hr\)
Question:The distance between centre of the earth and moon is 384000 km. If the mass of the earth is \(6 \times {10^{24}}kg\) and \(G = 6.66 \times {10^{ - 11}}N{m^2}/k{g^2}\). The speed of the moon is nearly
1 km/sec
4 km/sec
8 km/sec
11.2 km/sec
Question:If satellite is shifted towards the earth. Then time period of satellite will be
Increase
Decrease
Unchanged
Nothing can be said
Question:Which of the following quantities does not depend upon the orbital radius of the satellite
\(\frac{T}{R}\)
\(\frac{{{T^2}}}{R}\)
\(\frac{{{T^2}}}{{{R^2}}}\)
\(\frac{{{T^2}}}{{{R^3}}}\)
Question:The time period of a satellite of earth is 5 hours. If the separation between the earth and the satellite is increased to four times the previous value, the new time period will become
20 hours
10 hours
80 hours
40 hours
Question:The gravitational force between two stones of mass 1 kg each separated by a distance of 1 metre in vacuum is
\(6.675 \times {10^{ - 5}}\,newton\)
\(6.675 \times {10^{ - 11}}\,newton\)
\(6.675 \times {10^{ - 8}}\,newton\)
Question:Two particles of equal mass go round a circle of radius R under the action of their mutual gravitational attraction. The speed of each particle is
\(v = \frac{1}{{2R}}\sqrt {\frac{1}{{Gm}}} \)
\(v = \sqrt {\frac{{Gm}}{{2R}}} \)
\(v = \frac{1}{2}\sqrt {\frac{{Gm}}{R}} \)
\(v = \sqrt {\frac{{4Gm}}{R}} \)
Question:The earth (mass \( = 6 \times {10^{24}}\,kg)\)) revolves round the sun with angular velocity \(2 \times {10^{ - 7}}\,rad/s\) in a circular orbit of radius \(1.5 \times {10^8}\,km\). The force exerted by the sun on the earth in newtons, is
\(18 \times {10^{25}}\)
\(27 \times {10^{39}}\)
\(36 \times {10^{21}}\)
Question:Two identical solid copper spheres of radius R placed in contact with each other. The gravitational attracton between them is proportional to
R\(^2\)
R\(^{ - 2}\)
R\(^{\rm{4}}\)
R\(^{--{\rm{4}}}\)
Question: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 forced of attraction between the planet and the star is proportional to \({R^{ - 5/2}}\), then:
\({{\rm{T}}^{\rm{2}}}\) is proportional to \({R^3}\)
\({{\rm{T}}^{\rm{2}}}\) is proportional to \({R^{7/2}}\)
\({{\rm{T}}^{\rm{2}}}\) is proportional to \({R^{3/2}}\)
Question: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
\(\frac{1}{2}\)mgR
2 mgR
mgR
\(\frac{1}{4}\)mgR