Miscellaneous Mensuration (Simple) | Learn Mathematics Online

Miscellaneous Mensuration (Simple)

Study Material (PDF)

Study Material (PDF)

Click on each question to see answer & solution.

Question No: #21

The length of outer and inner radii of a hollow right circular pipe are 5 cm and 4 cm respectively. If the total surface area of the pipe is 1188 sq. cm, find the length of the pipe.

Ans: 20 cm.

Question No: #22

The height and the radius of the base of a right circular cylinder are in the ratio `3:1`. If its volume is `1029\pi` `\text{cm}^3`, find its total surface area.

Ans: 1232 sq.cm.

Question No: #23

If a pump set with a pipe of 14 cm diameter can drain 2500 metres water per minute, then calculate how much kilolitres water will that pump drain per hour.

Ans: 2310 kilo-liters

Question No: #24

An outlet pipe in the roof with length 13 m. and breadth 11 m. was closed at the time of rain fall. After rain fall, it was seen that water having logged in the roof with 7 cm. depth. The length of diameter of outlet pipe is 7 cm. and water comes our cylindrically with 200 m. length/min. Calculate the time required is drainout whole amount of water after opening the pipe.

Ans: 13 minutes

Question No: #25

A pump with a diameter of 4 cm can lift 175 liters of water per minute. How many minutes will the pump run to fill an empty tank of 2.2 m long, 1.8 m wide and 1 m high?

Ans: 18 minutes

Question No: #26

A right circular cylindrical tank of 9 metres height is filled with water. Water comes out from there through a pipe having length of 6 cm diameter with a speed of 225 metre per minute and the tank becomes empty after 36 minutes. Calculate the length of radius of the tank.

Ans: 1.8 m

Question No: #27

A group of fire brigade personnel carried a right-circular cylindrical tank filled with water and pumped out water at a speed of 420 meters per minute to put out the fire in 40 minutes by three hose pipes of 2 cm diameter each. If the diameter of the tank is 2⋅8 meters and its length is 6 meters, then calculate (i) how much water (in liters) has been spent in putting out the fire and (ii) how much water (in liters) that still remains in the tank.

Ans: (i) 15840 lt, (ii) 21120 lt

Question No: #28

The diameter of cross-section of a wire is reduced by 50%. If the volume remains constant, then what percent of length of the wire should be increased?

Ans: 300%

Question No: #29

The geometric name of a solid with a single vertex is ........ .

Ans: cone (শঙ্কু)

Question No: #30

State true or false.
(i) In a right circular cone, height, radius and slant height are always be the three sides of a right angled triangle.
(ii) If the volume of a right circular cone be `V` cubic-unit and the area of the base be `A` sq-unit, then the height of the cone is `{3V}/A` unit.
(iii) The volume of a right-circular cone remains the same if the length of the base radius is halved and the height is doubled.

Ans: (i) True, (ii) True , (iii) False