61. Who said, '' The true shape of planets orbit is elliptical (oval) "

1. 1. Gabileo

   
   
   

   2. Kepler

   
   
   

   3. Copernicus

   
   
   

   4. Iderschel

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: B

   NA

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62. Which planet has the longest day and the shortest year ?

1. 1. Mars

   
   
   

   2. Jupitor

   
   
   

   3. Mercury

   
   
   

   4. Uranus

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: C

   NA

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63. The maen radius of the earth is-

1. 1. 3200 km

   
   
   

   2. 6400 km

   
   
   

   3. 9600 km

   
   
   

   4. 12800 km

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: B

   NA

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64. On planet Earth, there is no centrifugal force at the

1. 1. Equator

   
   
   

   2. Tropic of Cancer

   
   
   

   3. Tropic of Capricorn

   
   
   

   4. Poles

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: D

   NA

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65. Which one of the following is present in the largest amount in terms of percent by mass in the earth's crust ?

1. 1. Silicon

   
   
   

   2. Oxygen

   
   
   

   3. Carbon

   
   
   

   4. Calcium

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: B

   NA

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