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The volume of a metallic cylindrical pipe is 748 cm3. Its length is 14 cm and external radius is 9 cm. Its thickness is
(Use π = 22/7 )
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- 1 cm
- 7 cm
- 17 cm
- 11 cm
- 1 cm
Correct Option: A
According to the question, π(R² – r²) h = 748
| ⇒ | (R² – r²) × 14 = 748 | |
| 7 |
| ⇒ R² – r² = | = 17 | |
| 22 × 14 |
⇒ 9² – r² = 17
⇒ 81 – r² = 17
⇒ r² = 81 – 17 = 64
⇒ r = 64 = 8 cm.
∴ Thickness of pipe = R – r = 9 – 8 = 1 cm.
