501. First controlled fission of an atom was carried out in ________ on 1938.
A. U.S
B. Germany
C. Russia
D. U.K

502. Short sightedness is due to__________?
A. Shifting of the iris
B. Elongation of eyeballs
C. Weakening of the retina
D. Weaker muscles

503. Underground water and the water on the earth’s surface is called ?
A. Mezosphere
B. Ionosphere
C. Hydrosphere
D. None of these

504. Which of the following is not a fat soluble vitamin?
A. Vitamin A
B. Vitamin D
C. Vitamin B complex
D. Vitamin K

505. What is total area of the earth?
A. 510.94 million km²
B. 492.102 million km²
C. 392.023 million km²
D. 692.192 million km²

506. which of the following planets has no moons ?
A. Mars
B. Neptune
C. Venus
D. None of these

507. The first and largest asteroid discovered was__________?
A. Pallas
B. Juno
C. Ceres
D. Trojan

508. The mean distance of the earth from the sun is astronomical units is____________?
A. 3.7 AU
B. 10 AU
C. 1 AU
D. 101 AU

509. Which Civilization developed & implemented the first solar calendar?
A. Babylonian
B. Greek
C. Egyptian
D. Aztec

510. The nearest Star to the planet earth is ________ ?
A. Regel
B. Canopus
C. Sun
D. Betelgeuse