9th class Physics unit 5 MCQs
chapter 5 MCQs 9th Class Physics
Gravitation:
1. Earth’s gravitational force of attraction vanishes at:
a. 42300 km
b. 6400 km
c. 1000 km
d. infinity
2. The idea of gravity was first put by:
a. Hooke
b. Galileo
c. Einstein
d. Isaac Newton
3. A force which is inversely proportional to the square of the distance between the centres of bodies is:
a. Centripetal force
b. Frictional force
c. Gravitational force
d. Centrifugal force
4. Value of Gravitational constant ‘G’ is:
a. 6.67 x 10-11 Nm2Kg-2
b. 6.67 x 10-9 Nm2Kg-2
c. 6.67 x 10-12 Nm2Kg-2
d. 6.67 x 10-10 Nm2Kg-2
5. Near the surface of Earth, the gravitational field strength is:
a. 8 Nkg-1
b. 5 Nkg-1
c. 10 Nkg-1
d. 6 Nkg-1
6. The value of g on Moon’s surface is 1.6 ms . What will be the weight of a 100 kg body on the surface of the Moon?
a. 100 N
b. 10 N
c. 160 N
d. 16 N
7. Formula of mass of Earth is:
a. Me=gR3G2
b. Me=gR3G
c. Me=gRG2
d. Me=gR2G
8. The mass of Earth is:
a. 6 x 1024 Kg
b. 6 x 104 Kg
c. 6 x 10-24 Kg
d. 6 x 1014 Kg
9. The mass of a boy is 40 kg. its weight on Earth will be:
a. 400 N
b. 200 N
c. 500 N
d. 300 N
10. The value of “g” increases with the:
a. Decrease in altitude
b. Increase in mass of the body
c. Increases in altitude
d. None of the above
11. Value of ‘g’ at sea-level is ……… than hill:
a. Equal
b. Less
c. Half
d. Greater
12. The value of ‘g’ at Moon is:
a. 1.6 ms-1
b. 1.6 ms-2
c. 1.6 km-1
d. 1.6 cms-2
13. The value of ‘g’ at Jupiter is:
a. 10 ms-2
b. 1.62 ms-2
c. 25.94 ms-2
d. 9.8 ms-2
14. The value of “g” on the surface of Mars is:
a. 8.87 ms-2
b. 3.73 ms-2
c. 10 ms-2
d. 1.62 ms-2
15. The altitude of geostationary orbits in which communication satellites are launched above the surface of the Earth is:
a. 6,400 km
b. 850 km
c. 42,300 km
d. 1000 km
16. The orbital speed of a low orbit satellite is:
a. 800 ms-1
b. Zero
c. 8000 ms-1
d. 8 ms-1
17. The speed of geostationary satellite with respect to Earth is:
a. Zero
b. Double
c. Less
d. Same
18. The total number of satellites in global positioning system is:
a. 24
b. 12
c. 25
d. 22
19. The speed of a satellite nearest to the Earth’s orbit is:
a. 8 kms-1
b. 6 kms-1
c. 10 kms-1
d. 7 kms-1
20. The height of a geostationary satellite is about:
a. 10,000 km
b. 42,300 km
c. 38,000 km
d. 6,400 km
21. The moon is nearly ……… away from the Earth:
a. 37,000 km
b. 3,80,000 km
c. 37,0000 km
d. 3,800 km
22. The moon completes its one rotation around the Earth in:
a. 29.3 days
b. 25.3 days
c. 31.3 days
d. 27.3 days
23. The centripetal acceleration is inversely proportional to:
a. Radius
b. Mass
c. Mass and radius
d. Velocity
24. Centripetal force is directly proportional to:
a. V
b. m2
c. R
d. v2
25. The velocity of geostationary satellites with respect to Earth is:
a. 10 kmh-1
b. Zero
c. 15 kmh-1
d. 5 kmh-1
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