01Hard159×since 2002Q7166The acceleration due to gravity at height hhh above the earth if h<<Rh << \mathrm{R}h<<R (Radius of earth) is given byAg′=g(1−2hR)g^{\prime}=g\left(1-\frac{2 h}{R}\right)g′=g(1−R2h)Bg′=g(1−2h2R2)g^{\prime}=g\left(1-\frac{2 h^{2}}{R^{2}}\right)g′=g(1−R22h2)Cg′=g(1−h22R2)g^{\prime}=g\left(1-\frac{h^{2}}{2 R^{2}}\right)g′=g(1−2R2h2)Dg′=g(1−h2R)g^{\prime}=g\left(1-\frac{h}{2 R}\right)g′=g(1−2Rh)Check answerSkip
02Medium159×since 2002Q7167The weight of a body on the earth is 400 N400 \mathrm{~N}400 N. Then weight of the body when taken to a depth half of the radius of the earth will be:A300 NB200 NC100 NDZeroCheck answerSkip
03Hard159×since 2002Q7168The weight of a body on the surface of the earth is 100 N100 \mathrm{~N}100 N. The gravitational force on it when taken at a height, from the surface of earth, equal to one-fourth the radius of the earth is:A50 NB64 NC25 ND100 NCheck answerSkip
04Medium159×since 2002Q7179The mass of a spaceship is 100010001000 kg.kg.kg. It is to be launched from the earth's surface out into free space. The value of ggg and RRR (radius of earth ) are 10 m/s210\,m/{s^2}10m/s2 and 640064006400 kmkmkm respectively. The required energy for this work will be:A6.4×1011 6.4 \times {10^{11}}\,6.4×1011 JoulesB6.4×108 6.4 \times {10^8}\,6.4×108 JoulesC6.4×109 6.4 \times {10^9}\,6.4×109 JoulesD6.4×1010 6.4 \times {10^{10}}\,6.4×1010 JoulesCheck answerSkip
05Hard159×since 2002Q7169If R\mathrm{R}R is the radius of the earth and the acceleration due to gravity on the surface of earth is g=π2 m/s2g=\pi^2 \mathrm{~m} / \mathrm{s}^2g=π2 m/s2, then the length of the second's pendulum at a height h=2R\mathrm{h}=2 Rh=2R from the surface of earth will be, :A19 m\frac{1}{9} \mathrm{~m}91 mB89 m\frac{8}{9} \mathrm{~m}98 mC29 m\frac{2}{9} \mathrm{~m}92 mD49 m\frac{4}{9} \mathrm{~m}94 mCheck answerSkip
06Easy159×since 2002Q7170The acceleration due to gravity on the surface of earth is g\mathrm{g}g. If the diameter of earth reduces to half of its original value and mass remains constant, then acceleration due to gravity on the surface of earth would be :Ag/4B2gCg/2D4gCheck answerSkip
07Medium159×since 2002Q7171At what distance above and below the surface of the earth a body will have same weight. (take radius of earth as RRR.)A3R−R2\frac{\sqrt{3} R-R}{2}23R−RBR2\frac{R}{2}2RC5R−R2\frac{\sqrt{5} R-R}{2}25R−RD5R−R\sqrt{5} R-R5R−RCheck answerSkip
08Hard159×since 2002Q7172A 90 kg90 \mathrm{~kg}90 kg body placed at 2R2 \mathrm{R}2R distance from surface of earth experiences gravitational pull of : (R=\mathrm{R}=R= Radius of earth, g=10 m s−2\mathrm{g}=10 \mathrm{~m} \mathrm{~s}^{-2}g=10 m s−2)A300 NB225 NC100 ND120 NCheck answerSkip
09Medium159×since 2002Q7173Assuming the earth to be a sphere of uniform mass density, a body weighed 300 N300 \mathrm{~N}300 N on the surface of earth. How much it would weigh at R/4 depth under surface of earth ?A75 NB375 NC300 ND225 NCheck answerSkip
10Easy159×since 2002Q7174The escape velocity of a body depends upon mass asAm0{m^0}m0Bm1{m^1}m1Cm2{m^2}m2Dm3{m^3}m3Check answerSkip