Saved Bookmarks
| 1. |
A wire of length 88cm and diameter 0.4mm has a resistance of 6ohm . calculate the specific resistance of the material of wire |
|
Answer» The required SPECIFIC resistance of the wire is approximately 0.86 × 10⁻⁶ Ω-mExplanation:Given :length of the wire = 88 cmdiameter of the wire = 0.4 mmresistance of the wire = 6 ΩTo FIND :the specific resistance of the material of wireSolution :The resistance of a wire is given by, whereρ denotes the specific resistancel denotes the LENGTHA denotes the AREA of cross SECTION⇒ length = 88 cmlength = 0.88 m⇒ diameter = 0.4 mmradius = 0.4/2 = 0.2 mmradius = 0.2 × 10⁻³ m⇒ Area of cross section = πr²Area = (22/7) × (0.2 × 10⁻³)²Area = (22/7) × 0.04 × 10⁻⁶Area = 0.88/7 × 10⁻⁶ m² Substitute the values, ∴ The specific resistance of the given wire is approximately 0.86 × 10⁻⁶ Ω-m |
|