Multiple choice

A figure is formed by revolving a rectangular sheet of dimensions 7 cm × 4 cm about its length. What is the volume of the figure thus formed? 7 सेमी. × 4 सेमी विमा वाली एक आयताकार चादर को अपनी लम्बाई के परितः परिक्रमण कराने से एक आकृति बनती है। इस प्रकार निर्मित आकृति का आयतन क्या है?

  1. 352 cm2/सेमी2

  2. 296 cm2/सेमी2

  3. 176 cm2/सेमी2

  4. 616 cm2/सेमी2
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

When a rectangle of dimensions 7cm × 4cm is revolved about its length (7cm), it forms a cylinder with height = 7cm and radius = 4cm (the width becomes the radius). Volume = πr²h = π(4)²(7) = 112π cm³. Using π = 22/7: 112 × 22/7 = 16 × 22 = 352 cm³. Note: Option A shows cm² but should be cm³ - this is a unit error.

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