ABC26GN4924 · Volume and Surface Area

Subject: General Aptitude · Chapter: Volume and Surface Area · Exam: 2005 · Marks: · Difficulty:

A copper rod of 1 cm diameter and 8 cm length is drawn into a wire of uniform diameter and 18 m length. The radius (in cm) of the wire is,

(a)$\frac{1}{15}$

(b)$\frac{1}{30}$

(c)$\frac{2}{15}$

(d)15 ![](

Answer

Answer (as printed): B

Explanation

Volume of copper rod =  π × × × 8 cm = 2 π cm . 2 2 Let the radius of the wire be r cm. Then, volume of wire = (pr2 × 1800) cm3 = 1800 pr2 cm3. 2 1 1 1 \ 1800 pr2 = 2p ⇒ r2 = = ⇒r= = . 1800 900 900 30

Explanation as extracted from the printed page; notation may be imperfect.

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