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Kepler discovered

(a) Laws of motion (b) Laws of rotational motion (c) Laws of planetory motion (d) Laws of curvilinear motion Answer: c (6)

The earth revolves round the sun in one year. If the distance between them becomes double, the new period of revolution will be

(a) 1/2 year (b) 2√2 years (c) 4 years (d) 8 years Answer: b (4)

If mass of a satellite is doubled and time period remain constant the ratio of orbit in the two cases will be

(a) 1 : 2 (b) 1 : 1 (c) 1 : 3 (d) None of these Answer: b (5)

A satellite A of mass m is at a distance of r from the centre of the earth. Another satellite B of mass 2m is at a distance of 2r from the earth’s centre. Their time periods are in the …

Planetary system in the solar system describes

(a) Conservation of energy (b) Conservation of linear momentum (c) Conservation of angular momentum (d) None of these Answer: c (6)

If the radius of earth’s orbit is made 1/4, the duration of an year will become

(a) 8 times (b) 4 times (c) 1/8 times (d) 1/4 times Answer: c (22)

The period of revolution of planet A around the sun is 8 times that of B. The distance of A from the sun is how many times greater than that of B from the sun

(a) 2 ( b) 3 (c) 4 (d) 5 Answer: c (6)

According to Kepler, the period of revolution of a planet (T) and its mean distance from the sun (r) are related by the equation (a) T3 r3 = constant (b) T2 r–3 = constant (c) Tr3 = constant …

107.

The mean distance between the atoms of iron is 3×10-10 m and interatomic force constant for iron is 7 N/m. The Young’s modulus of elasticity for iron is (a) 2.33×105 N/m2 (b) 23.3×1010 …

106. A uniform plank of Young’s modulus Y is moved over a smooth horizontal surface by a constant horizontal force F. The area of cross section of the plank is A. The compressive strain on the plank in the direction of the force is

(a) F/(AY) (b) (2F)/(AY) (c) 1/2{ F/(AY)} …

29. Which one of the following statements regarding artificial satellite of the earth is incorrect

(a) The orbital velocity depends on the mass of the satellite (b) A minimum velocity of 8 km/sec is required by a satellite to orbit quite close to the earth (c) The period of revolution is large if the radius …

23.

The moment of inertia of a rod of length l about an axis passing through its centre of mass and perpendicular to rod is I. The moment of inertia of hexagonal shape formed by six such rods, about an axis …

The orbital speed of Jupiter is

(a) Greater than the orbital speed of earth (b) Less than the orbital speed of earth (c) Equal to the orbital speed of earth (d) Zero Answer: b (15)

105. A pan with set of weights is attached with a light spring. When disturbed, the mass-spring system oscillates with a time period of 0.6 s. When some additional weights are added then time period is 0.7s. The extension caused by the additional weights is approximately given by

(a) 1.38 cm (b) 3.5 cm (c) 1.75 cm (d) 2.45 cm Answer-b (36)

Kepler’s second law regarding constancy of aerial velocity of a planet is a consequence of the law of conservation of

(a) Energy (b) Angular momen (c) Linear momentum (d) None of these Answer: b (4)

The earth E moves in an elliptical orbit with the sun S at one of the foci as shown in figure. Its speed of motion will be maximum at the point

Answer: b (13)

A planet revolves around sun whose mean distance is 1.588 times the mean distance between earth and sun. The revolution time of planet will be

(a) 1.25 years (b) 1.59 years (c) 0.89 years (d) 2 years Answer: d (8)

The rotation period of an earth satellite close to the surface of the earth is 83 minutes. The time period of another earth satellite in an orbit at a distance of three earth radii from its surface will be

(a) 83 minutes (b) 83 × √8 minutes (c) 664 minutes (d) 249 minutes Answer:c (6)

A satellite moves around the earth in a circular orbit of radius r with speed v. If the mass of the satellite is M, its total energy is

(a) -(1/2)Mv2 (b) (1/2)Mv2 (c) (3/2)Mv2 (d) Mv2 Answer: a (5)

A satellite whose mass is M, is revolving in circular orbit of radius r around the earth. Time of revolution of satellite is

Answer: b (10)

A satellite moves round the earth in a circular orbit of radius R making one revolution per day. A second satellite moving in a circular orbit, moves round the earth once in 8 days. The radius of the orbit of the second satellite is

(a) 8 R (b) 4R (c) 2R (d) R Answer: b (5)

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

(a) 20 hours (b) 10 hours (c) 80 hours (d) 40 hours Answer: d (3)

Which of the following quantities does not depend upon the orbital radius of the satellite

(a) T/R (b) T/R2 (c) T2/ R2 …

If satellite is shifted towards the earth. Then time period of satellite will be

(a) Increase (b) Decrease (c) Unchanged (d) Nothing can be said Answer: b (6)

An artificial satellite is placed into a circular orbit around earth at such a height that it always remains above a definite place on the surface of earth. Its height from the surface of earth is

(a) 6400 km (b) 4800 km (c) 32000 km (d) 36000 km Answer: d (4)

The weight of an astronaut, in an artificial satellite revolving around the earth, is

(a) Zero (b) Equal to that on the earth (c) More than that on the earth (d) Less than that on the earth Answer: a (48)

98. The length of an elastic string is a metre when the longitudinal tension is 4 N and b metre when the longitudinal tension is 5 N. The length of the string in metre when the longitudinal tension is 9 N is

(a) a-b (b) 5b-4a (c) 2b-(1/4)a …

97. When a uniform wire of radius r is stretched by a 2kg weight, the increase in its length is 2.00 mm. If the radius of the wire is r/2 and other conditions remain the same, the increase in its length is

(a) 2.00 mm (b) 4.00 mm (c) 6.00mm (d) 8.00 mm Answer-d (10)

104. According to Hook’s law of elasticity, if stress is increased, the ratio of stress to strain

(a) Increases (b) Decreases (c) Becomes zero (d) Remains constant Answer-d (9)

A person sitting in a chair in a satellite feels weightless because

(a) The earth does not attract the objects in a satellite (b) The normal force by the chair on the person balances the earth’s attraction (c) The normal force is zero (d) The person in satellite is not accelerated Answer: …