NEET Mechanical Properties of Solids — Set 2

Question 1

A copper rod of radius $ 0.02 \, \text{m} $ and length $ 1.0 \, \text{m} $ is subjected to a tensile force producing a stress of $ 2 \times 10^7 \, \text{N/m}^2 $. What is the force applied? (Take $ \pi \approx 3.14 $)

Accepted Answer

Stress: $ \text{Stress} = \frac{F}{A} $. Area: $ A = \pi r^2 = 3.14 \times (0.02)^2 = 3.14 \times 4 \times 10^{-4} = 1.256 \times 10^{-3} \, \text{m}^2 $. Force: $ F = \text{Stress} \times A = 2 \times 10^7 \times 1.256 \times 10^{-3} = 2.512 \times 10^4 \, \text{N} $.

Question 2

Why are I-shaped beams commonly used in construction for load-bearing applications?

Accepted Answer

I-shaped beams provide a large load-bearing surface and sufficient depth to reduce bending, minimizing buckling while reducing weight compared to solid beams.

Question 3

A steel wire of length 2.5 m and cross-sectional area 3 × 10 -6 m 2 is stretched by a force producing a strain of 2 × 10 -4 . If the Young's modulus of steel is 2 × 10 11 N/m 2 , what is the force applied?

Accepted Answer

Young's modulus: Y = Stress / Strain. Stress: Stress = Y × Strain = 2 × 10 11 × 2 × 10 -4 = 4 × 10 7 N/m 2 . Force: F = Stress × A = 4 × 10 7 × 3 × 10 -6 = 120 N.

NEET Physics: Mechanical Properties of Solids — Practice Set 2

Q1. A copper rod of radius \( 0.02 \, \text{m} \) and length \( 1.0 \, \text{m} \) is subjected to a tensile force producing a stress of \( 2 \times 10^7 \, \text{N/m}^2 \). What is the force applied? (Take \( \pi \approx 3.14 \))

Q2. Why are I-shaped beams commonly used in construction for load-bearing applications?

Q3. A steel wire of length 2.5 m and cross-sectional area 3 × 10 -6 m 2 is stretched by a force producing a strain of 2 × 10 -4 . If the Young's modulus of steel is 2 × 10 11 N/m 2 , what is the force applied?

Q4. A copper wire of length 1 m and cross-sectional area 1 × 10 -6 m 2 is stretched by a force of 50 N. If the Young's modulus of copper is 1.1 × 10 11 N/m 2 , what is the elongation?

Q5. A steel wire of length \( 2.5 \, \text{m} \) and cross-sectional area \( 2 \times 10^{-6} \, \text{m}^2 \) is stretched by a force producing a strain of \( 3 \times 10^{-4} \). If the Young's modulus of steel is \( 2 \times 10^{11} \, \text{N/m}^2 \), what is the force applied?

Q6. Which type of stress leads to a change in length of a body without changing its shape?

Q7. A copper wire of length \( 1.6 \, \text{m} \) and cross-sectional area \( 1.8 \times 10^{-6} \, \text{m}^2 \) is stretched by a force of \( 180 \, \text{N} \). If the Young's modulus of copper is \( 1.1 \times 10^{11} \, \text{N/m}^2 \), what is the elongation?

Q8. In the stress-strain behavior of a material, what occurs after the maximum stress point when the material is ductile?

Q9. What does the steepness of the initial linear portion of a stress-strain curve indicate?

Q10. A glass slab of volume \( 0.02 \, \text{m}^3 \) is subjected to a hydraulic pressure of \( 3 \times 10^6 \, \text{N/m}^2 \). If the bulk modulus of glass is \( 3.7 \times 10^{10} \, \text{N/m}^2 \), what is the fractional change in volume?