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The volume of a cylinder with radius 7 cm and height 10 cm is:
1540 cm³
770 cm³
3080 cm³
1240 cm³
1540 cm³
Since the radius is a multiple of 7, use π=722 to easily cancel out the 7 in r2, saving calculation time in the exam hall.
Radius of the cylinder r = 7 cm, Height of the cylinder h = 10 cm
V=πr2h
Since the radius is a multiple of 7, use π=722 to easily cancel out the 7 in r2, saving calculation time in the exam hall.
Students often use the diameter instead of the radius or accidentally use the formula for the curved surface area instead of the volume.
Identify Given Parameters
Note down the radius and height provided in the question: radius r=7 cm and height h=10 cm.
r=7 cm,h=10 cm
Recall the Volume Formula
The formula for the volume of a cylinder is the product of the base area and the height: V=πr2h.
V=πr2h
Substitute Values and Calculate
Substitute π=722, r=7, and h=10 into the formula to compute the final volume.
V=722×(7)2×10=722×49×10=22×7×10=1540 cm3
A is correct because the calculated volume of the cylinder is 1540 cm³.
Understanding cylinder volume formulas is essential for solving composite solid problems in mensuration and surface area topics for technical exams.