Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
Concepts Of Physics MCQ Edition [Volume 1]
Exam
Concepts Of Physics MCQ Edition [Volume 1]
Subject
Physics
Chapter
Some Mechanical Properties of Matter

Concepts Of Physics MCQ Edition [Volume 1] · Physics · Some Mechanical Properties of Matter

A load of 10 kg is suspended by a metal wire that is 3 m long and...

A load of 10 kg10 \text{ kg} is suspended by a metal wire that is 3 m3 \text{ m} long and possesses a cross-sectional area of 4 mm24 \text{ mm}^2. Determine the stress. The Young modulus of the metal is 2.0×1011 N/m22.0 \times 10^{11} \text{ N/m}^2.

Options

  1. A2.5×105 N/m22.5 \times 10^5 \text{ N/m}^2
  2. B2.45×107 N/m22.45 \times 10^7 \text{ N/m}^2
  3. C2.5×107 N/m22.5 \times 10^7 \text{ N/m}^2
  4. D2.5×106 N/m22.5 \times 10^6 \text{ N/m}^2

Correct answer

B. 2.45×107 N/m22.45 \times 10^7 \text{ N/m}^2

Step-by-step solution

Given mass of the load, m=10 kgm = 10 \text{ kg}

Cross-sectional area, A=4 mm2=4×10−6 m2A = 4 \text{ mm}^2 = 4 \times 10^{-6} \text{ m}^2

Acceleration due to gravity, g=9.8 m/s2g = 9.8 \text{ m/s}^2

The restoring force developed in the wire is equal to the weight of the suspended load.

F=mg=10×9.8=98 NF = mg = 10 \times 9.8 = 98 \text{ N}

Stress is defined as the restoring force per unit area.

Stress=FA\text{Stress} = \dfrac{F}{A}

Stress=984×10−6=24.5×106 N/m2\text{Stress} = \dfrac{98}{4 \times 10^{-6}} = 24.5 \times 10^6 \text{ N/m}^2

Stress=2.45×107 N/m2\text{Stress} = 2.45 \times 10^7 \text{ N/m}^2
Practice Some Mechanical Properties of Matter on Quantrex Academy →

More from Some Mechanical Properties of Matter

A vertical metal cylinder of radius 2 cm and length 2 m is fixed at its lower end, and a… Concepts Of Physics MCQ Edition [Volume 1]A vertical metal cylinder of radius 2 cm and length 2 m is fixed at its lower end, and a… Concepts Of Physics MCQ Edition [Volume 1]A load of 10 kg is suspended by a metal wire that is 3 m long and possesses a… Concepts Of Physics MCQ Edition [Volume 1]A load of 10 kg is suspended by a metal wire that is 3 m long and possesses a… Concepts Of Physics MCQ Edition [Volume 1]A vertical metal cylinder of radius 2 cm and length 2 m is fixed at its lower end, and a… Concepts Of Physics MCQ Edition [Volume 1]Steel has an elastic limit of 8 × 10^8 N/m^2 and a Young modulus of 2 × 10^ 11 N/m^2 .… Concepts Of Physics MCQ Edition [Volume 1]A steel wire and a copper wire, both possessing equal length and equal cross-sectional… Concepts Of Physics MCQ Edition [Volume 1]A steel wire and a copper wire, both possessing equal length and equal cross-sectional… Concepts Of Physics MCQ Edition [Volume 1] Full Some Mechanical Properties of Matter list All Concepts Of Physics MCQ Edition [Volume 1] PYQs