Question
A solid cylinder has the total surface area 231 sq.cm.
If its curved surface area is of the total surface area, then the volume of the cylinder isSolution
Total surface area = 231 cm2 Curved surface area = 2/3 x 231 = 154 cm2 Curved surface area of cylinder = 2πrh ⇒ 2πrh = 154 ⇒ 2 × (22/7) × r × h = 154 ⇒ r × l = 24.5 Total surface area of cylinder = 2πr(r + h) ⇒ 2πr(r + h) = 231 ⇒ r(r + h) = 36.75 ⇒ r2 + rh = 36.75 ⇒ r2 = 36.75 - 24.5 ⇒ r2 = 12.25 ⇒ r = 3.5 cm Volume of cylinder = πr2h ⇒ π × r × (r × h) ⇒ π × 3.5 × 24.5 ⇒ 269.5 cm ∴ The volume of the cylinder is 269.5 cm3 .
Which one of the following lymphoid organ is large at birth but reduces with age ?Â
- Which hormone is secreted when blood sugar levels are low?
Match List-I with List-II :
Choose the correct answe...
Plants are divided into ______ groups.
Which antibodies are present in individuals with blood group AB?
Measles is caused by ______.
The term ‘GEAC’ stands for:
Which plants have root nodules?
Which disease is known as the 'silent killer' because it often has no symptoms but can cause heart attack or stroke?
DPT vaccine does not give protection to a child from