1. If density of earth increased 4 times and its radius become half of what it is, our weight will

a) Be four times its present value

b) Be doubled

c) Remain same

d) Be halved

Explanation:

2. A man can jump to a height of 1.5 m on a planet A. What is the height he may be able to jump on another planet whose density and radius are,respectively, one-quarter and one-third that of
planet A

a) 1.5 m

b) 15 m

c) 18 m

d) 28 m

Explanation:

3. Weight of a body is maximum at

a) Moon

b) Poles of earth

c) Equator of earth

d) Centre of earth

Explanation: Poles of earth

4. What will be the acceleration due to gravity at height h if h >> R. Where R is radius of earth and g is acceleration due to gravity on the surface of
earth

a) \[\frac{g}{\left(1+\frac{h}{R}\right)^{2}}\]

b) \[g{\left(1-\frac{2h}{R}\right)}\]

c) \[\frac{g}{\left(1-\frac{h}{R}\right)^{2}}\]

d) \[g{\left(1-\frac{h}{R}\right)}\]

Explanation:

5. The acceleration due to gravity near the surface of a planet of radius R and density d is proportional to

a) \[\frac{d}{R^{2}}\]

b) \[dR^{2}\]

c) dR

d) \[\frac{d}{R}\]

Explanation:

6. The acceleration due to gravity is g at a point distant r from the centre of earth of radius R. If \[r<R\] , then

a) \[g\propto r\]

b) \[g\propto r^{2}\]

c) \[g\propto r^{-1}\]

d) \[g\propto r^{-2}\]

Explanation:

7. A body weight W newton at the surface of the earth. Its weight at a height equal to half the radius of the earth will be

a) \[\frac{W}{2}\]

b) \[\frac{2W}{3}\]

c) \[\frac{4W}{9}\]

d) \[\frac{8W}{27}\]

Explanation:

8. If the density of the earth is doubled keeping its radius constant then acceleration due to gravity will be \[\left(g=9.8m\diagup s^{2}\right)\]

a) 19.6 \[m\diagup s^{2}\]

b) 9.8 \[m\diagup s^{2}\]

c) 4.9 \[m\diagup s^{2}\]

d) 2.45 \[m\diagup s^{2}\]

Explanation:

9. The acceleration due to gravity at pole and equator can be related as

a) \[g_{p} < g_{e}\]

b) \[g_{p}=g_{e}=g\]

c) \[g_{p}=g_{e}<g\]

d) \[g_{p} > g_{e}\]

Explanation: \[g_{p} > g_{e}\]

10. A research satellite of mass 200 kg circles the earth in an orbit of average radius 3R/2 where R is the radius of the earth. Assuming the
gravitational pull on a mass of 1 kg on the earth’s surface to be 10 N, the pull on the satellite will be

a) 880 N

b) 889 N

c) 890 N

d) 892 N

Explanation: