Easy Tutorial
For Competitive Exams

NEET - Physics Gravitation Practice Q & A

26204.If ‘r’ represents the radius of the orbit of a satellite of mass ‘m’ moving round a planet of mass ‘M’, the velocity of the satellite is given by
v2 = $\dfrac{gM}{r}$
v2 = $\dfrac{GMm}{r}$
v = $\sqrt{\dfrac{GM}{r}}$
v = $\dfrac{GM}{r^{2}}$
26205.When the planet comes nearer the sun moves
fast
slow
constant at every point
none of the above
26206.Kepler’s second law regarding constancy of arial velocity of a planet is a consequence of the law of conservation of
energy
angular momentum
linear momentum
none of these
26207.The relation between escape velocity and orbit velocity is
ve = $\sqrt{2v}_{orb}$
ve = $\dfrac{1}{\sqrt{2}}v_{orb}$
ve = $2v_{orb}$
ve = $\sqrt{3}v_{orb}$
26208.A geostationary satellite is orbiting the earth at a height of 6R above the surface of the earth, R being the radius of the earth. The time period of another satellite at a height of 2.5 R from the surface of earth is
6$\sqrt{2}$ hr
6 hr
5$\sqrt{2}$ hr
10 hr
26209.The distance of Neptune and Saturn from the sun are nearly 1013 m and 1012 m respectively. Assuming that they move in circular orbits, their periodic times would be in the ratio of
10
100
10 $\sqrt{10}$
1000
26210.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 force of attraction between the planet and the star is proportional to R-5/2 then
T2 \propto R2
T2 \propto R7/2
T2 \propto R3/2
T2 \propto R3
26211.The acceleration due to gravity g and mean density of the earth ρ are related by which of
the following relation? Where g is gravitational constant and R is radius of the earth
ρ = $\dfrac{4\pi gR^{2}}{3G}$
ρ = $\dfrac{4\pi gR^{3}}{3G}$
ρ = $\dfrac{3g}{4\pi GR}$
ρ = $\dfrac{3g}{4\pi GR^{3}}$
26212.If the earth is 1/4th of its present distance from the sun, the duration of the year would be
1/4 of the present year
1/6 of the present year
1/8 of the present year
1/16 of the present year
26213.A planet has twice the radius but the mean density is 1/4th as compared to earth. What is the radio of the escape velocity from the earth to that from the planet?
3 : 1
1 : 2
1 : 1
2 : 1
26214.A missile is launched with a velocity less than the escape velocity. The sum of its kinetic and potential energy is
Positive
Negative
Zero
may be positive or negative
26215.The distance between centre of the earth and moon is 384000 km. If the mass of the earth is 6 × 1024 kg and G = 6.66 × 10–11 Nm2/kg2. The speed of the moon is nearly
1 km/sec
4 km/sec
8 km/sec
11.2 km/sec
26216.If the radius of the earth were to shrink by 1% its mass remaining the same, the acceleration due to gravity on the earth’s surface would
decrease by 2%
remain unchanged
increase by 2%
will increase by 9.8%
26217.The escape velocity of projection from the earth is approximately (R = 6400 km)
7 km/sec
112 km/sec
12.2 km/sec
1.1 km/sec
26218.There is no atmosphere on the moon because
it is closer ot the earth
it revolves round the earth
it gets light from the sun
the escape velocity of gas molecules is less than their root mean square velocity here
26219.Fg and Fe represents gravitational and electrostatic forces respectively, between the two electrons situated at a distance of 10 m. The ratio Fg/Fe is of the order of
1043
1036
10–43
10–36
26220.If the acceleration due to gravity of a planet is half the acceleration due to gravity of earth’s surface and radius of planet is half the radius of the earth, the mass of planet in terms of mass of earth is
$\dfrac{M_{e}}{2}$
$\dfrac{M_{e}}{4}$
$\dfrac{M_{e}}{6}$
$\dfrac{M_{e}}{8}$
26221.The value of ‘g’ at a particular point is 9.8 m/sec2 suppose the earth suddenly shrink uniformly to half its present size without losing any mass. The value of ‘g’ at the same point (assuming that the distance of the point from the centre of the earth does not shrink) will become
9.8 m/sec2
4.9 m/sec2
19.6 m/sec2
2.45 m/sec2
26222.A thin uniform, circular ring is rolling down an inclined plane of inclination 30° without slipping. Its linear acceleration along the inclined plane will be
g/2
g/3
g/4
2g/3
26223.The period of geostationary artificial satellite of earth is
6 hours
12 hours
24 hours
365 days
Share with Friends