Gravitation - Olympiad Level MCQ, Class 9 Science - Class 9 MCQ

# Gravitation - Olympiad Level MCQ, Class 9 Science - Class 9 MCQ

Test Description

## 25 Questions MCQ Test - Gravitation - Olympiad Level MCQ, Class 9 Science

Gravitation - Olympiad Level MCQ, Class 9 Science for Class 9 2024 is part of Class 9 preparation. The Gravitation - Olympiad Level MCQ, Class 9 Science questions and answers have been prepared according to the Class 9 exam syllabus.The Gravitation - Olympiad Level MCQ, Class 9 Science MCQs are made for Class 9 2024 Exam. Find important definitions, questions, notes, meanings, examples, exercises, MCQs and online tests for Gravitation - Olympiad Level MCQ, Class 9 Science below.
Solutions of Gravitation - Olympiad Level MCQ, Class 9 Science questions in English are available as part of our course for Class 9 & Gravitation - Olympiad Level MCQ, Class 9 Science solutions in Hindi for Class 9 course. Download more important topics, notes, lectures and mock test series for Class 9 Exam by signing up for free. Attempt Gravitation - Olympiad Level MCQ, Class 9 Science | 25 questions in 25 minutes | Mock test for Class 9 preparation | Free important questions MCQ to study for Class 9 Exam | Download free PDF with solutions
Gravitation - Olympiad Level MCQ, Class 9 Science - Question 1

### A satellite which is geostationary in a particular orbit is taken to another orbit. Its distance from the centre of earth in new orbit is 2 times that of the earlier orbit. The time period in the second orbit is

Gravitation - Olympiad Level MCQ, Class 9 Science - Question 2

### Two metal spheres of equal radius r are touching each other. The force of attraction F between them is

 1 Crore+ students have signed up on EduRev. Have you?
Gravitation - Olympiad Level MCQ, Class 9 Science - Question 3

### A man weighs 60 kg at earth's surface. At what height above the earth's surface his weight becomes 30 kg? (radius of earth = 6400 km).

Gravitation - Olympiad Level MCQ, Class 9 Science - Question 4

There are two bodies of masses 100 kg and 10000 kg separated by a distance 1m. At what distance from

the smaller body, intensity of gravitational field will be zero?

Detailed Solution for Gravitation - Olympiad Level MCQ, Class 9 Science - Question 4
Gravitation - Olympiad Level MCQ, Class 9 Science - Question 5

At what height, is the value of g half that on the surface of earth? (R = radius of the earth)

Detailed Solution for Gravitation - Olympiad Level MCQ, Class 9 Science - Question 5
G at surface of earth = (G*M /R^2 ) where G is universal gravitational constant and M is mass of the earth and R is radius of the earth or (simply the distance of a object from the centre of earth ) ..if g should be half that experienced at the surface then R becomes √2 times R .Hence the height at which one will experience g/2 acceleration is when he is at a distance(√2–1 )R from the surface of earth.
[ at distance of 0.414 R approx .]
Gravitation - Olympiad Level MCQ, Class 9 Science - Question 6

A planet of mass m moves around the sun of mass M in an elliptical orbit. The maximum and minimum distances

of the planet from the sun are r1 and r2 respectively. The time period ofthe planet is proportional to

Detailed Solution for Gravitation - Olympiad Level MCQ, Class 9 Science - Question 6
Gravitation - Olympiad Level MCQ, Class 9 Science - Question 7

On a planet (whose size is the same and mass 4 times as that of the earth), the energy needed to lift a

2 kg mass vertically upwards through 2 m distance on the planet is (g = 10 m/s2 on the surface of the earth)

Gravitation - Olympiad Level MCQ, Class 9 Science - Question 8

A satellite is revolving in a circular orbit at a distance of 2620 km from the surface of the earth. The time

period of revolution of the satellite is (Radius of the earth = 6380 km, mass of the earth = 6 × 1024 kg,

G = 6.67 × 10-11 N-m2/kg2)

Gravitation - Olympiad Level MCQ, Class 9 Science - Question 9

On the surface of the earth, force of gravitational attraction between two masses kept at distance d apart

is 6 Newtons. If these two masses are taken to the surface of the moon and kept at the same distance d,

the force between them will be

Gravitation - Olympiad Level MCQ, Class 9 Science - Question 10

Time period of simple pendulum in a satellite is

Detailed Solution for Gravitation - Olympiad Level MCQ, Class 9 Science - Question 10
A satelite is a freely falling body. Hence g = 0 inside the satellite. From the expression of time period, for g =0, Time period of simple pendulum will be infinite. That means that the pendulum will not oscillate at all.
Gravitation - Olympiad Level MCQ, Class 9 Science - Question 11

A ball is dropped from a spacecraft revolving around the earth at height of 120 km. What will happen to

the ball ?

Gravitation - Olympiad Level MCQ, Class 9 Science - Question 12

The value of the acceleration due to gravity at a height of 12,800 km from the surface of the earth

Gravitation - Olympiad Level MCQ, Class 9 Science - Question 13

The weight of a body of mass 5 kg is :-

Gravitation - Olympiad Level MCQ, Class 9 Science - Question 14

The weight of the body at the surface of the earth is 20 N and the radius of the earth is 6400 km. The

weight of a body at a height 6400 km above is :-

Gravitation - Olympiad Level MCQ, Class 9 Science - Question 15

Consider a heavenly body which has a mass twice that of the earth and a radius thrice that of the earth. The

weight of a book on this heavenly body, if its weight on the earth is 900 N will be :-

Gravitation - Olympiad Level MCQ, Class 9 Science - Question 16

Two protons are kept at a separation of 1 femtometre (1 femtometre = 10-15 m). The mass of a proton is

1.67 × 10-27 kg. The gravitational force between them is :-

Gravitation - Olympiad Level MCQ, Class 9 Science - Question 17

The mass of the sun is 2.0 × 1036 kg and that of the earth is 6.0 × 1024 kg. The distance between the

sun and the earth is 1.5 × 1011 m. The gravitational force between the sun and earth is :-

Gravitation - Olympiad Level MCQ, Class 9 Science - Question 18

A particle is taken to a height of 2Re above the earth's surface, where Re is the radius of the earth. If it is

dropped from this height, its acceleration is will be :-

Gravitation - Olympiad Level MCQ, Class 9 Science - Question 19

Consider a heavenly body whose mass is 3 × 1024 kg (half of that of the earth) and radius is 3200 km (half

of that of the earth). The acceleratin due to gravity at the surface of this heavenly body will be :-

Gravitation - Olympiad Level MCQ, Class 9 Science - Question 20

Two bodies 'A' and 'B' having masses 'm' and '2m' respectively are kept at a distance 'd' apart. A small particle

is to be placed so that the net gravitational force on it, due to the bodies A and B, is zero. Its distance from

the mass A should be :-

Gravitation - Olympiad Level MCQ, Class 9 Science - Question 21

Two bodies of masses 1 kg and 2 kg respectively are placed at a separation of 1 m. Find the accelerations

of the bodies assuming that only gravitational force acts between them :-

Gravitation - Olympiad Level MCQ, Class 9 Science - Question 22

Communication satellites move in the orbits of radius 44,400 km around the earth. The acceleration of such

a satellite assuming that the only force acting on it is that due to the earth is :-

Detailed Solution for Gravitation - Olympiad Level MCQ, Class 9 Science - Question 22
Given, Radius of the orbit of the satellite, r = R+h = 44400 km = 444 * 10^5 m
Mass of the earth, Me = 6 * 10^24 kg
Universal gravitational constant, G = 6.67 * 10^-11 Nm^2kg^-2

Now, the acceleration of the satellite,  a = (G * Me ) / r^2
= {(6.67 * 10^-11) * (6 * 10^24)} / (444 * 10^5)^2

= (40.02 * 10^13 ) / (197136 * 10^10 )

= 0.20301 m/s^2 .
Gravitation - Olympiad Level MCQ, Class 9 Science - Question 23

Two persons weighing 50 kg and 60 kg are seated across a table. If they are one metre apart, the

gravitational force between them is :-

Gravitation - Olympiad Level MCQ, Class 9 Science - Question 24

The mass of a planet is twice and its radius is 3 times that of the earth. The weight of a body, which has

a mass of 5 kg on the surface of the earth, on that planet is :-

Gravitation - Olympiad Level MCQ, Class 9 Science - Question 25

The height at which a body has one fourth of its weight when it is on the surface of the earth is :-