Total surface area of cylinder = 2πr(h + r)
Given that, r = 14/2 = 7 cm, h = 40 cm

Correct Option: A

Total surface area of cylinder = 2πr(h + r)
Given that, r = 14/2 = 7 cm, h = 40 cm
∴ Required total surface area = 2 x (22/7) x 7 x (40 + 7)
= 44 x 47 = 2068 sq cm

Given, lateral surface area = 94.2 sq cm
⇒ 2πrh = 94.2
∴ r = 94.2/(2πh)

Correct Option: C

Given, lateral surface area = 94.2 sq cm
⇒ 2πrh = 94.2
∴ r = 94.2/(2πh) = 94.2/(2 x 3.14 x 5) = 3 cm

Given,
r₁ = 1 cm, h₁ = 30 cm, h₂ = 300 cm.
Volume of rod = Volume of wire
⇒ πr₁²h₁ = πr²₂h₂

Correct Option: B

Given, r₁ = 1 cm, h₁ = 30 cm, h₂ = 300 cm.
Volume of rod = Volume of wire
⇒ πr₁²h₁ = πr²₂h₂
⇒ π x (1)² x 30 = π x r²₂ x 300
⇒ r²₂ = 30/300
∴ r₂ = 1/√10 cm
∴ diameter = 2r₂
= 2 x 1/√10 = 2/√10cm.

Let the height and radius and radius of solid cylinder be h and r cm respectively
Given that, radius (r) = 5 cm
and total surface area = 660 cm²
⇒ 2πrh + 2πr² = 660

Correct Option: D

Let the height and radius and radius of solid cylinder be h and r cm respectively
Given that, radius (r) = 5 cm
and total surface area = 660 cm²
⇒ 2πrh + 2πr² = 660
⇒ 2πr(h + r) = 660
⇒ (h + 5) = 330/5π = 330/5 x 7/22
⇒ h = 66 x (7/22) - 5 = 21 - 5
∴ Required height = 16 cm

Curved surface area of the cylinder = 2πrh

Correct Option: D

Curved surface area of the cylinder = 2πrh
= 2 x (22/7) x 7 x 160
= 7040 sq cm