Question

<!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> The total surface area of a right circular cylinder is 352 <!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> $m^2$. If the radius of the base of the cylinder is 7 m, find its height.

• A. 8 m
• B. 4.5 m
• C. 1 m

Answer 1

The correct option is C 1 m

Given,

Total surface area of the right circular cylinder = 352 <!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> $m^2$

Radius of the base of the cylinder, r = 7 m

Total surface area of a right circular cylinder = 2$\pi$rh + 2$\pi$$r^2$ ----- (i)

Putting r = 7 in equation (i) we get,

Total surface area of the cylinder
= (2 × $\frac{22}{7}$ × 7 × h) + (2 × $\frac{22}{7}$ × $7^2$)

= 44h + 308

According to the question,

44h + 308 = 352

⇒ 44h = 44

⇒ h = 1 m

∴ Height of the cylinder is 1 m.