(a) 4.2 years (b) 2.8 years (c) 5.6 years (d) 8.4 years Answer: b (7)
(a) A (b) B (c) C (d) D Answer: c (12)
(a) The time taken in travelling DAB is less than that for BCD (b) The time taken in travelling DAB is greater than that for BCD (c) The time taken in travelling CDA is less than that for ABC (d) …
(a) 53/2 years (b) 52/3years (c) 51/3 years (d) 51/2 years Answer: a (5)
(a) Copernicus (b) Kepler (c) Galileo (d) None Answer: A (6)
A satellite of mass m is circulating around the earth with constant angular velocity. If radius of the orbit is R0 and mass of the earth M, the angular momentum about the centre of the earth is (a) m√GMR0 …
The largest and the shortest distance of the earth from the sun are r1 and r2 , its distance from the sun when it is at the perpendicular to the major axis of the orbit drawn from the sun (a) …
Two planets move around the sun. The periodic times and the mean radii of the orbits are T1 , T2and r1 ,r2 respectively. The ratio T1/T2 is equal to (a) ( r1 /r2 )1/2 …
A planet moves around the sun. At a given point P, it is closest from the sun at a distance d1 and has a speed v1 . At another point Q, when it is farthest from the sun at a distance …
The earth revolves about the sun in an elliptical orbit with mean radius 9.3 × 107 in a period of 1 year. Assuming that there are no outside influences (a) The earth’s kinetic energy remains constant (b) The earth’s angular …
The figure shows the motion of a planet around the sun in an elliptical orbit with sun at the focus. The shaded areas A and B are also shown in the figure which can be assumed to be equal . …
The distance of neptune 1013 and 1012 saturn from sun are nearly and meters respectively. Assuming that they move in circular orbits, their periodic times will be in the ratio (a) √10 …
When a satellite going round the earth in a circular orbit of radius r and speed v loses some of its energy, then r and v change as (a) r and v both with increase (b) r and v both …
In planetary motion the areal velocity of position vector of a planet depends on angular velocity (ω) and the distance of the planet from sun (r). If so the correct relation for areal velocity is Answer: c (8)
Two planets at mean distance d1 and d2 from the sun and their frequencies are n1 and n2 respectively then Answer: b (11)
Potential energy of a satellite having mass ‘m’ and rotating at a height of 6.4 × 106m from the earth surface is (a) -0.5 mgRe (b) -mgRe (c) -2 …
A satellite with kinetic energy Ek is revolving round the earth in a circular orbit. How much more kinetic energy should be given to it so that it may just escape into outer space (a) Ek (b) 2 Ek …
If the gravitational force between two objects were proportional to 1/R (and not as 1/R2) where R is separation between them, then a particle in circular orbit under such a force would have its orbital speed v proportional to (a) …
Distance of geostationary satellite from the surface of earth radius (Re =6400 km )in terms of Re) is (a) 13.76 Re (b) 10.76 Re (c) 6.56 Re …
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 × 10-11Nm2/kg2. The speed of the moon is nearly (a) 1 km/sec (b) …
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] Answer: c (9)
The orbital speed of an artificial satellite very close to the surface of the earth is V° . Then the orbital speed of another artificial satellite at a height equal to three times the radius of the earth is (a) …
Two satellites of masses m1 and m2( m1>m2 ) are revolving round the earth in circular orbits of radius r1 and r2( r1>r2 ) Which of the following statements is true regarding their speeds v1 and v2 ? (a) v1 …
3 particles each of mass m are kept at vertices of an equilateral triangle of side L. The gravitational field at centre due to these particles is (a) Zero (b) 3GM/L2 (c) 9 GM/L2 (d) ( 12/√3) (GM/L2) Answer: …
A particle of mass 10 g is kept on the surface of a uniform sphere of mass 100 kg and radius 10 cm. Find the work to be done against the gravitational force between them to take the particle far …
The escape velocity from earth is ves. A body is projected with velocity 2 ves with what constant velocity will it move in the inter planetary space (a) ves (b) 3ves (c) √3 …
A planet has twice the radius but the mean density is 1/4 th as compared to earth. What is the ratio of escape velocity from earth to that from the planet (a) 3 : 1 …
The acceleration due to gravity on a planet is same as that on earth and its radius is four times that of earth. What will be the value of escape velocity on that planet if it is ve on earth …
The escape velocity for a body of mass 1 kg from the earth surface is 11.2 kms-1 The escape velocity for a body of mass 100 kg would be (a) 11.2 × 102 kms-2 …
The escape velocity for the earth is ve . The escape velocity for a planet whose radius is four times and density is nine times that of the earth, is (a) 36 ve (b) 12 ve (c) 6 ve (d) 20 ve Answer: b …
The radius of a planet is 1/4 of earth’s radius and its acceleration due to gravity is double that of earth’s acceleration due to gravity. How many times will the escape velocity at the planet’s surface be as compared to …
The escape velocity of a body on an imaginary planet which is thrice the radius of the earth and double the mass of the earth is ( ve is the escape velocity of earth) (a) √2/3 ve …
A mass of 6 × 1024 kg is to be compressed in a sphere in such a way that the escape velocity from the sphere is 3 × 108 m/s . Radius of the sphere should be (G = 6.67×10-11 N-m2/kg2) …
The ratio of the radii of planets A and B is k1 and ratio of acceleration due to gravity on them is k2. The ratio of escape velocities from them will be (a) k1 k2 …
How many times is escape velocity ( Ve ) , of orbital velocity (V0 )for a satellite revolving near earth (a) √2 times (b) 2 times (c) 3 times (d) 4 times Answer: a (8)
The least velocity required to throw a body away from the surface of a planet so that it may not return is (radius of the planet is ( 6.4×106 m, g=9.8 m/sec2) (a) 9.8 ×10-3 m/sec …
How much energy will be necessary for making a body of 500 kg escape from the earth [g=9.8 m/s2 , radius of earth 6.4×106 m] (a) About 9.8×106 J (b) About 6.4×108 J (c) …
v e and vp denotes the escape velocity from the earth and another planet having twice the radius and the same mean density as the earth. Then (a) ve = vp …