## Wednesday, September 5, 2012

### Physics Objective Question Paper for UPSC IAS Exams

Physics Objective Question Paper for UPSC IAS Exams
MCQ Physics UPSC Practice Test
UPSC Exam material Physics objective questions and answers1. The masses of 10 kg and 20 kg respectively are connected by a mass less spring as shown in the figure. A force of 200 N acts on the 20 kg mass. At the instant shown, the 10 kg mass has acceleration 12 rn/sec2. What is the acceleration of 20 kg mass—

(A) 12 m/sec2
(B) 4 m/sec2
(C) 10 m/sec2
(D)  Zero
Ans:-B

2. Which of the following laws helps us to find out the distances of the radio galaxies?
(A) Kepler’s law
(B) Doppler’s effect
(C) Hubble’s law
(D) Newton’s law of gravitation
Ans:-C

3. Which of the following is more abundant in the universe?
(A) Planets
(B) Stars
(C) Both ‘A’ and ‘B’
(D) None of ‘A’ and ‘B’
Ans:-B

4. The first woman in space is—
(A) Svetina Savitskaya
(B) Sally Ride
(C) Valentina Tereshkova
(D) None of the above
Ans:-C

5. A star that gives off radio waves is—
(A) neutron
(B) Supernova
(C) Pulsar
(D) all of the above
Ans:-C

6. The exterior planets are composed of—
(A) Hydrogen
(B) Helium
(C) Both ‘A’ and ‘B’
(D) None of ‘A’ and ‘B’
Ans:-C

7. The spherical density of the galaxy due to itself remains—
(A) Changeable
(B) Unchangeable
(C) Both ‘A’ and ‘B’
(D) None of ‘A’ and ‘B’
Ans:-B

8. Let Î» be the mean free path of molecules in a given gas. Then the probability that any molecule transverses a distance x without suffering a collision is proportional to:

Ans. (d)

9. Match List I with List II and select the correct answer using the codes given below the Lists:
Codes:
A         B         C         D
(a)        2          4          1          3
(b)        3          1          4          2
(c)        2          1          4          3
(d)       3          4          1          2
Ans. (c)

10. An electromagnetic wave propagates through a non-magnetic medium which has two parameters. These are dielectric constant, Îµ and refractive index n. The relationship between them is:
(a) Îµ2 = n
(b) √Îµ = n
(c) Îµ = Kn where K is constant
(d) Îµ + n = 1
Ans. (b)

11. When an electromagnetic wave is incident on a perfectly conducting plane.
1. There is no change in phase of
2. The phase of changes by ÐŸ
3. All the energy gets absorbed.
4. All the energy gets reflected.
Which of these is/are correct?
(a) 1 and 4
(c) 2 and 4
(b) 1 and 3
(d) 3 only
Ans. (c)

12. Match List I (Gates) with List II (Mathematical characteristics) and select the correct answer using the codes given below the Lists:
Codes:
A         B         C         D
(a)        2          3          4          1
(b)        4          1          2          3
(c)        2          1          4          3
(d)       4          3          2          1

Ans. (b)

13. Which of the following planets is deemed to be farthest from the earth?
(A) Saturn
(B) Pluto
(C) Venus
(D) Jupiter
Ans:-B

14. What is the number of planets in the solar system?
(A) four
(B) Seven
(C) five
(D) nine
Ans:-D

15. Which of the following planets has rings around it?
(A) Saturn
(B) Uranus
(C) Mars
(D) Jupiter
Ans:-A

16. Below the earth-crust is situated—
(A) Core
(B) Outer core
(C) Mantle
(D) None of these
Ans:-C

17. A projectile is fired with a speed u at an angle Î¸ with the horizontal. Its speed when its direction of motion makes an angle a with the horizontal is—
(A) u cos Î± sec Î¸
(B) u cos Î¸ sec Î¬
(C) u sin Î¸ tan Î¬
(D) u cos Î¸ cot Î±
Ans:-B

18. According to Big-Bang theory there happend to take palce a gigantic explosion in the condensed state of the universe. As a consequence of it, what happened to the universe?
(A) Expansion
(B) Division
(C) Destruction
(D) Nothing happened
Ans:-A

19. Which of the following is capable of checking the expansion of the universe?
(A) Gravitation
(B) Light
(C) Sound
(D) all of the above
Ans:-A

20. An explosive star that produces, a high luminescence is a—
(A) supernova
(B)  Neutron
(C)  Pulsar
(D)  None of  the these
Ans:-A

21. The first spaceman is—
(A) Neil Armstrong
(B) Yuri Gagarin
(C) Aleksey A Leohov
(D) None of the above
Ans:-B

22. On which of the following theories is the constitution of the planets and the earth based?
(A) Copernicus theory
(B) Lithosphere theory
(C) Einstein’s theory
(D) All of the above
Ans:-A

23. The modern geologists have ascertained the age of the earth as—
(A) 4600 crore years
(B) 4000 crore years
(C) 200 crore years
(D) 1600 crore years
Ans:-A

24. All the inner planets are composed of—
(A) Hydrogen
(B) Helium
(C) Rocks
(D) None of these
Ans:-C

25. The planet Venus lies between—
(A) Mercury and earth
(B) Earth and mars
(C) Sun and Earth
(D) Jupiter and Saturn
Ans:-A