Question

1. The visible region of the sun is known as a. corona b. photosphere c. radiation zone d. chromosphere

2. The average temperature of that part of the sun, which we see, is (a) 6000 k (b) 60,000 k (c) 600 k (d) 15 million k

3. Granulation of the sun is caused by a. sunspots b. prominences c. convection d. radiation

4. Convection zone is located a. next to the core b. between radiation zone and photosphere c. between chromospheres and corona d. between the earth and the sun

5. What is the hottest part of the entire Sun? a. Radiation zone b. core c. corona d. photosphere

6. What is the most abundant element in the sun? a. Hydrogen b. Uranium c. carbon d. Oxygen

7. How many stars are there in our solar system? (a) 1 (b) 200 million (c) 8 (d) 0

8. As the sun produces energy, its mass a. increases b. decreases c. remains the same

9. Two stars, A & B, appears in same color. This implies that a. Both stars emit same amount of light. b. Both stars located at equal distance from the earth. c. Both stars has the same temperature. d. None of the above

10. Luminosity of a star depends on a. distance and temperature b. brightness and distance c. size and distance d) size and temperature

11. Apparent brightness of a star depends on a. temperature and distance (c) distance only b. size and distance (d) distance and luminosity

12. If parallax of a star is 0.5 arc sec, its distance is a. 0.5 ly b. 0.5 pc c. 2 pc d. 2 ly Use the information in following table to answer questions 13-18 Name Apparent brightness- m Absolute brightness M Spectral class Parallax Arc sec Alderbaran 1 1.5 M 0.3 Arcturus 0.1 -0.6 K 0.1 Capella 0.4 -4 G 0.18 Ross 3.4

13 B 0.28 Cygni 18 7 M 0.005 Procyon 0.4 3.7 A 0.55 Eridani 5 4 K 0.4 13. What is the hottest star? a. Capella b, Cygni c. Alderbaran d, Procyon

14. Which star is closest to the earth? a. Cygni b. Alderbaran c. Eridani d. Procyon

15. Which star has the greatest luminosity? a. Capella b, Eridini c. Alderbaran d, Ross

16. Which star is not visible to naked eye? a. Capella b, Cygni c. Sirius d, Ross

17. Compare Arcturus and Eridani, Which star is bigger a. arcturus b. Eridani c. both stars have same size

18. What is the spectral class of the Sun? a) A b) B c) M d) G

19. A star has apparent brightens 3 and absolute brightness 1. The distance to this star from the earth is a. 3 light years b. less than 10 pc c. more than 10 pc d. 100 l.y

20. Sun is known as a normal star, but it appears very bright because a. it has very large luminosity b. its core temperature is very high compared to all other stars c. It is much bigger than all other stars d. It is very close to the earth.

Part 2:

1. Name some of the surface features of the Sun.

2. What type of radiation sun emits most?

3. Explain the energy production method of the sun.

4. Explain how astronomers measure the distance to near by stars. What kind of measurements are required to calculate the distance to a particular star?

5. Astronomers can measure the temperature of stars very accurately. Explain the method use by astronomers to calculate the temperature of stars.

Answer 1

First Four Questions –

(1) The visible surface of the sun is PHOTOSPHERE.

Hence option (b) is the correct answer.

(2) The average temperature of photosphere, which we see is 6000 Kelvins.

Hence option (a) is the correct answer.

(3) Granulation on the photosphere of the sun is caused by convection currents of plasma within the sun’s convective zone.

Hence option (c) CONVECTION, is the correct answer.

(4) The convection zone is the outer-most layer of the interior of the sun. Hence this layer is located between the earth and the sun.

Hence option (d) is the correct answer.