NTA Abhyas 2020
- Exam
- NTA Abhyas
- Year
- 2020
- Subject
- Physics
- Chapter
- Mechanical Properties of Solids
NTA Abhyas 2020 · Physics · Mechanical Properties of Solids
Two wires of diameter 0.25 cm, one made of steel and other made of...
Two wires of diameter 0.25 cm, one made of steel and other made of brass are loaded as shown in figure. The unloaded length of steel wire is 1.5 m& and that of brass wire is 1.0 m. Young's modulus of steel is 2.0 × 10^{11}& and Young's modulus & of Brass& 0.91 × 10^{11} Pa. The elongations of steel and brass wires are respectively


Options
- A1.3 × 10^{-2}& m;
1.5 × 10^{-4} m - B1.5 × 10^{-4}& m;
1.3 × 10^{-4} m - C2.0 × 10^{-5}& m;
1.8 × 10^{-3} m - D1.8 × 10^{-3}& m;
2.1 × 10^{-3} m
Correct answer
B. 1.5 × 10^{-4}& m;
1.3 × 10^{-4} m
Step-by-step solution
Given, diameter of wires (2r)=0.25 cm r=0.125 cm=1.25 × 10^{-3} m For steel wire, Load (F_{1})=(4 + 6) kgf=10 × 9.8 N=98 N Length of steel wire (l_{1})=1.5 m Young's modulus (Y_{1})=2.0 × 10^{11} Pa =1.5 × 10^{-4} m For brass wire, Load (F_{2})=6 kgf=6 × 9.8 N=58.8 N Length of brass wire (l_{2})=1.0 m Young's modulus (Y_{2})=0.91 × 10^{11} Pa =1.3 × 10^{-4} m