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CBSE Class 11 Physics Chapter 10 Mechanical Properties of Solids MCQ
The study of Mechanical Properties of Solids is crucial for understanding how materials respond to various forces and conditions. In CBSE Class 11 Physics, this chapter delves into key concepts such as stress, strain, elasticity, and plasticity. Students will explore how solids deform under external forces, the relationship between stress and strain, and the significance of properties like Young’s modulus and tensile strength.
To enhance their learning experience, students can access a variety of resources, including mechanical properties of solids MCQ class 11 materials. These multiple-choice questions are designed to test comprehension and application of the chapter’s concepts. Additionally, students can find mechanical properties of solids MCQ PDF downloads for convenient offline study.
For those preparing for exams, practicing with mechanics of solids MCQ with answers PDF can be particularly beneficial. This practice helps reinforce knowledge and improves problem-solving skills. Furthermore, while this chapter focuses on solids, understanding these principles lays the groundwork for exploring related topics in mechanical properties of fluids, which is covered in subsequent chapters.
Class 11 Physics Mechanical Properties of Solids Overview
Here’s an overview of class 11 physics chapter 10 Mechanical Properties of Solids:
Mechanical Properties of Solids
This chapter delves into the study of how solid materials respond to external forces. It explores the various ways in which solids deform under stress and the factors that influence these deformations. The key concepts covered include:
Stress: The force acting per unit area within a deformable body. It is a measure of the internal forces resisting deformation.
- Tensile Stress: Arises when a force tends to stretch or elongate the body.
- Compressive Stress: Occurs when a force tends to compress or shorten the body.
- Shear Stress: Develops when forces act parallel to the surface of the body, causing it to deform by sliding.
Strain: The relative deformation or change in shape or size of a body under stress. It is a dimensionless quantity.
- Longitudinal Strain: Change in length per unit original length.
- Volume Strain: Change in volume per unit original volume.
- Shear Strain: Angular deformation resulting from shear stress.
Elasticity: The property of a material to regain its original shape and size after the removal of deforming forces.
Plasticity: The property of a material to undergo permanent deformation without breaking.
Hooke’s Law: Within the elastic limit, stress is directly proportional to strain. This linear relationship is represented by the modulus of elasticity.
Modulus of Elasticity: The ratio of stress to strain within the elastic limit.
- Young’s Modulus: Measures the resistance of a material to tensile or compressive stress.
- Bulk Modulus: Measures the resistance of a material to volume change under uniform pressure.
- Shear Modulus: Measures the resistance of a material to shear deformation.
Elastic Limit: The maximum stress a material can withstand before it starts to deform plastically.
Breaking Stress or Tensile Strength: The maximum stress a material can withstand before it breaks.
Ductility: The property of a material to be drawn into wires.
Malleability: The property of a material to be hammered into thin sheets.
Brittleness: The property of a material to break easily under stress with little or no plastic deformation.
Key Objectives Claa 11 Phyics Chapter 9 Mechanical Properties of Solids
- Understand the concepts of stress and strain.
- Learn about different types of stress and strain.
- Explore the elastic and plastic behavior of materials.
- Understand Hooke’s Law and the modulus of elasticity.
- Gain knowledge of different types of moduli of elasticity.
- Learn about the mechanical properties of materials like ductility, malleability, and brittleness.
This overview provides a foundational understanding of the key concepts and topics covered in the “Mechanical Properties of Solids” chapter. I’m ready when you are to provide the MCQs for practice. Let’s test your understanding!
Class 11 Physics Mechanical Properties of Solids MCQ Questions with Answers
Question 1: There are two wires of the same material and same length, while the diameter of the second wire is two times the diameter of the first wire. Then the ratio of extension produced in the wires by applying the same load will be:
- (a) 1 : 1
- (b) 2 : 1
- (c) 1 : 2
- (d) 4 : 1
Answer: (d) 4 : 1
Explanation: The extension produced in a wire is inversely proportional to the cross-sectional area. Since the diameter of the second wire is twice that of the first, the area of the second wire will be four times that of the first (Area ∝ diameter²). Therefore, the extension of the second wire will be one-fourth of that of the first wire, resulting in a ratio of 4:1.
Question 2: Which of the following has no dimensions?
- (a) Strain
- (b) Angular velocity
- (c) Momentum
- (d) Angular momentum
Answer: (a) Strain
Explanation: Strain is a dimensionless quantity because it is the ratio of the change in length to the original length, both of which have the same unit, canceling out any dimensions.
Question 3: Which one of the following is not a unit of Young’s modulus?
- (a) Nm⁻¹
- (b) Nm⁻²
- (c) dyne cm⁻²
- (d) mega pascal
Answer: (a) Nm⁻¹
Explanation: Young’s modulus has units of pressure, which are force per unit area. Therefore, the correct units are Nm⁻² or pascals, not Nm⁻¹.
Question 4: According to Hooke’s law of elasticity, if stress is increased, then the ratio of stress to strain:
- (a) Becomes zero
- (b) Remains constant
- (c) Decreases
- (d) Increases
Answer: (b) Remains constant
Explanation: According to Hooke’s Law, stress is directly proportional to strain within the elastic limit, and the constant of proportionality is Young’s modulus. Therefore, the ratio of stress to strain remains constant.
Question 5: The length of an iron wire is L and the area of cross-section is A. The increase in length is l on applying a force F on its two ends. Which of the following statements is correct?
- (a) Increase in length is inversely proportional to its length
- (b) Increase in length is proportional to area of cross-section
- (c) Increase in length is inversely proportional to area of cross-section
- (d) Increase in length is proportional to Young’s modulus
Answer: (c) Increase in length is inversely proportional to area of cross-section
Explanation: From Hooke’s Law, the increase in length (l) is directly proportional to the applied force and the original length, and inversely proportional to the cross-sectional area of the wire. Therefore, the correct relation is that the increase in length is inversely proportional to the area of cross-section.
Question 6: A wire is stretched to double of its length. The strain is:
- (a) 2
- (b) 1
- (c) Zero
- (d) 0.5
Answer: (b) 1
Explanation: Strain is defined as the change in length divided by the original length. If the wire is stretched to double its length, the change in length is equal to the original length, thus strain = 1.
Question 7: Hooke’s law defines:
- (a) Stress
- (b) Strain
- (c) Modulus of elasticity
- (d) Elastic limit
Answer: (c) Modulus of elasticity
Explanation: Hooke’s law states that stress is directly proportional to strain within the elastic limit, and the constant of proportionality is the modulus of elasticity.
Question 8: In the case of a steel wire (or a metal wire), the limit is reached when:
- (a) The wire just breaks
- (b) The load is more than the weight of the wire
- (c) Elongation is inversely proportional to the tension
- (d) None of these
Answer: (d) None of these
Explanation: The elastic limit of a wire is reached when the wire can no longer return to its original shape after the removal of the applied stress, and it begins to deform plastically. The other options do not describe this phenomenon.
Question 9: When an elastic material with Young’s modulus Y is subjected to stretching stress S, the elastic energy stored per unit volume of the material is:
- (a) YS / 2
- (b) S²Y / 2
- (c) S² / 2Y
- (d) S / 2Y
Answer: (c) S² / 2Y
Explanation: The elastic potential energy stored per unit volume in an elastic material under stress is given by the formula U = S² / 2Y, where S is the stress and Y is Young’s modulus.
FAQs on Mechanical Properties of Solids MCQ Class 11 Physics
Are the MCQs aligned with the CBSE syllabus?
Yes, the Mechanical Properties of Solids MCQs are specifically designed to align with the Class 11 CBSE syllabus. They encompass all important topics outlined in the curriculum, ensuring that students are well-prepared for their examinations.
How can practicing these MCQs benefit students?
Regular practice of these MCQs helps students solidify their understanding of key concepts and improve their problem-solving skills. By familiarizing themselves with the types of questions typically asked in exams, students can enhance their accuracy and speed during assessments.
What topics are covered in the Mechanical Properties of Solids MCQs for Class 11?
The MCQs cover essential topics such as stress, strain, elasticity, Young's modulus, bulk modulus, and shear modulus. These concepts are fundamental for understanding how materials behave under various forces and are crucial for both CBSE board exams and competitive exams like NEET.
