Q.1
Which is of the following statement is true Statement A: Gravitational constant G value does not depend on the medium between the bodies Statement B: Gravitational constant G depends on the masses of the bodies and the sizes of the bodies
  • A & B both are correct
  • only A is correct
  • Only B is correct
  • A and B both are wrong
Q.2
If the distance between the earth and sun were half its present value, the number of days in a year would be
  • 64.5
  • 129
  • 182.5
  • 730
Q.3
if both the mass of earth and its radius are decreased by 1%,the value of acceleration of gravity will
  • Decrease by 1%
  • Increase by 1%
  • Increase by 2%
  • remain unchanged
Q.4
A body weigh W newton of the surface of the earth. Its weight at a height equal to half the radius of the earth will be
  • W/2
  • 2W/3
  • 4W/9
  • W/4
Q.5
when a stone of mass m is falling in the earth of mass M, the acceleration of the earth will be
  • zero
  • mg/M
  • Mg/m
  • g
Q.6
The weight of the object will be  ( More than one correct answer)
  • zero at the center of the earth
  • same in all the satellites
  • same at all the points on the surface of the earthcorrect
  • none of the above
Q.7
Which is of the following statement is true Statement A: it is possible to put an artificial satellite in an orbit such a way that it will remain always directly over New Delhi Statement B: An earth satellite continues to move in the orbit due to centripetal force provided by the burning of the fuel of its engine
  • A & B both are correct
  • only A is correct
  • Only B is correct
  • A and B both are wrong
Q.8
A mass m is divided into two part ym and (1-y)m .For a given separation, the value of y for which the gravitational attraction between the two pieces becomes maximum
  • 1/2
  • 3/5
  • 1
  • 2
Q.9
Two bodies of mass M and 2M are at rest at infinite separation. They move towards each other under the mutual gravitational attraction. Then at separation r ,which of the following is false
  • The total energy of the system is not zero
  • The force between them is zero
  • The center of the mass of the system is moving
  • none of the above
Q.10
The change in the graviational potential energy when a body of mass m is raised to a height nR above the surface of the earth is (here R is the radius of the earth)
  • $(\frac {n}{n+1}) mgR$
  • $(\frac {n}{n-1}) mgR$
  • nmgR
  • $\frac {mgR}{n}$
Q.11
Two planets of radii $R_1$ and $R_2$ are made from the same material . The ratio of the accelerations due to gravity $g_1 /g_2$ at the surfaces of the planets is
  • $\frac {R_1}{R_2}$
  • $\frac {R_2}{R_1}$
  • $(\frac {R_1}{R_2})^2$
  • $(\frac {R_2}{R_1})^2$
Q.12
Assertion: Angular speed of a planet around the sun increases, when it is closer to the sun. Reason: Total angular momentum of the system remains constant. Choose the correct one
  • Both assertion and reason are true and reason is the correct explanation of the assertion
  • Both assertion and reason are true but reason is not correct explanation of the assertion
  • Assertion is true, but reason is false
  • Both assertion and reason are false
  • Reason is true but assertion is false.
Q.13
Assertion: Total energy is conserved moving a satellite to higher orbit. Reason: Sum of change in PE and KE is same in magnitude and opposite in nature. Choose the correct one
  • Both assertion and reason are true and reason is the correct explanation of the assertion
  • Both assertion and reason are true but reason is not correct explanation of the assertion
  • Assertion is true, but reason is false.
  • Both assertion and reason are false.
  • Reason is true but assertion is false
Q.14
What would be the acceleration due to gravity at another planet, whose mass and radius are twice that of the earth?
  • g/4
  • g/2
  • g
  • g/3
Q.15
The radii of circular orbits of two satellites A and B of the earth, are 4R and R, respectively. If the speed of satellite A is 3V, then the speed of satellite B will be
  • 3V/4
  • 6V
  • 12V
  • 3V/2
Q.16
If we move from equator to pole, the value of acceleration due to gravity
  • first increases then decreases
  • remains same
  • decreases
  • increases
Q.17
For a satellite moving in an orbit around the earth, the ratio of  potential energy to kinetic energy is
  • 1/2
  • 2
  • $\sqrt 2$
  • $1/\sqrt 2$
Q.18
An artificial satellite moving in a circular orbit around the earth has a total (kinetic + potential) Energy $E_0$. Its potential energy is
  • $E_0$
  • $2E_0$
  • $-E_0$
  • $1.5E_0$
Q.19
The distance of a geostationary satellite from the centre of earth (radius R = 6400 km) is nearest to
  • 18R
  • 7R
  • 10R
  • 4R
Q.20
Assertion: The earth without its atmosphere would be inhospitably cold. Reason: All heat would escape in the absence of atmosphere. Choose the correct one
  • Both assertion and reason are true and reason is the correct explanation of the assertion.
  • Both assertion and reason are true but reason is not correct explanation of the assertion
  • Assertion is true, but reason is false.
  • Both assertion and reason are false
  • Reason is true but assertion is false.
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