Volume and Surface Area - General Questions (2)
| 9. | 50 men took a dip in a water tank 40 m long and 20 m broad on a religious day. If the average displacement of water by a man is 4 m3, then the rise in the water level in the tank will be: |
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Answer: Option B Explanation: Total volume of water displaced = (4 x 50) m3 = 200 m3.
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Rise in water level =
m 0.25 m = 25 cm.| 10. | A boat having a length 3 m and breadth 2 m is floating on a lake. The boat sinks by 1 cm when a man gets on it. The mass of the man is: |
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Answer: Option B Explanation:
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| 11. | A hollow iron pipe is 21 cm long and its external diameter is 8 cm. If the thickness of the pipe is 1 cm and iron weighs 8 g/cm3, then the weight of the pipe is: |
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Answer: Option B Explanation: External radius = 4 cm, Internal radius = 3 cm.
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| 12. | 66 cubic centimetres of silver is drawn into a wire 1 mm in diameter. The length of the wire in metres will be: |
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Answer: Option A Explanation: Let the length of the wire be h.
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| 13. | A hall is 15 m long and 12 m broad. If the sum of the areas of the floor and the ceiling is equal to the sum of the areas of four walls, the volume of the hall is: |
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Answer: Option C Explanation: 2(15 + 12) x h = 2(15 x 12)
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| 14. | In a shower, 5 cm of rain falls. The volume of water that falls on 1.5 hectares of ground is: |
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Answer: Option B Explanation: 1 hectare = 10,000 m2 So, Area = (1.5 x 10000) m2 = 15000 m2.
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| 15. | A right triangle with sides 3 cm, 4 cm and 5 cm is rotated the side of 3 cm to form a cone. The volume of the cone so formed is: |
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Answer: Option A Explanation:
Clearly, we have r = 3 cm and h = 4 cm.
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r2h =