NCERT Solutions for class 11 Physics Chapter 9: Mechanical properties of solids

NCERT Solutions for Class 11 Physics Chapter 9: Mechanical Properties of Solids are provided in this article below. Mechanical properties of solids define the various characteristics of solids such as their resistance to deformation and their strength.

Chapter 9 Mechanical Properties of Solids belongs to Unit 7 Properties of Bulk Matter. Unit 7 along with Unit 8 Thermodynamics and Unit 9 Behaviour of Perfect Gases and Kinetic Theory of Gases has a weightage of 20 marks in the Class 11 Examination. The Class 11 NCERT Solutions for Mechanical Properties of Solids discusses concepts such as Elastic behaviour of solids, Hooke’s law, and the Stress-strain curve.

Download PDF: NCERT Solutions for Class 11 Physics Chapter 9

NCERT Solutions for Class 11 Physics Chapter 9

Class 11 Physics Chapter 9 – Concepts Covered

Stress is the ratio of the internal force F, produced when a substance is deformed, to the area A over which the force acts.

$Stress = {F \over A}$

Strain is the ratio of the change in shape or size to the original shape or size. It is just a number and has no dimensions.

Strain is of 3 types – Longitudinal strain, Volumetric strain, and Shear strain

As per Hooke’s law, the ratio of stress to the corresponding strain produced within elastic limits is a constant. This constant is known as the modulus of elasticity.

$F_s = -kx$

For a solid, in wire or a thin rod form, Young’s modulus of elasticity is defined as the ratio of longitudinal stress to longitudinal strain within the elastic limit.

Young's Modulus

Poisson’s Ratio – The ratio of change in diameter (ΔD) to the original diameter (D) is known as lateral strain. The ratio of change in length (Δl) to the original length (l) is known as longitudinal strain. The ratio of lateral strain to the longitudinal strain is called Poisson’s ratio.

$Poisson's\ Ratio\ = {Lateral\ strain \over Longitudinal\ Strain}$

Class 11 Physics Chapter 9 Related Guides –

Stress and Strain	Elastic Moduli	Shear Modulus
Bulk Modulus	Shearing Stress	Yield Strength
Elastic Limit	Tensile Stress	Elastomers
Beam Deflection Formula	Solid Deformation	Stress Formula

Class 11 Physics Study Guides:

Difference between in Physics	Physics Formula	Class 11 Physics Notes
Relation between articles in Physics	Derivations in Physics	Physics Study Notes
NCERT Solutions for Class 11 Physics	Physics Constants	SI Units in Physics

CBSE CLASS XII Related Questions

1.
Derive an expression for the capacitance of a parallel plate capacitor of plate area A and plate separation d with air present between the plates.

View Solution

2.
Capacitors are manufactured with certain standard capacitances and working voltages. However, these standard values may not be the ones that are actually needed in a particular application. Two or more capacitors can be grouped in series or in parallel to achieve desired capacitance and voltage. When connected in series, the total capacitance decreases while the voltage rating increases, whereas in parallel connections, the total capacitance increases and maintains the same voltage rating. A capacitor stores energy in the electric field between its plates and stored energy is proportional to the square of the voltage and capacitance $U = \frac{1}{2}CV^2$, where symbols have their usual meanings.
Two capacitors, one of $3 \ \mu$F and the other of $6 \ \mu$F, are connected in series in the circuit as shown in the figure, for a long time. }

3.
Read the following paragraph and answer the questions that follow.
In an experiment with convex lens of focal length f, the screen is fixed at a distance D from the object. A student slowly moves the lens away from the object towards the screen and finds that she is able to form sharp image of the object for two positions of the lens. The distance between these two positions of the lens is d.

4.
A charged particle $+q$ in an electric field $\vec{E}$ experiences a force in the direction of the electric field. As a result, its kinetic energy changes. Similarly, the charged particle also experiences a force when it moves in a magnetic field $\vec{B}$. But this magnetic force is perpendicular to both velocity $\vec{v}$ of the charged particle and the magnetic field $\vec{B}$, so it cannot change the kinetic energy of the charged particle. Consider two charged particles 1 and 2 of masses $m$ and $\frac{m}{2}$ having charges $-q$ and $+2q$ respectively. They are accelerated from rest through the same potential difference $V$ and acquire kinetic energy $K_1$ and $K_2$. Then they enter in a region of uniform magnetic field $\vec{B}$ perpendicular to their velocities.

5.
Consider the nuclear reaction $ X \to Y + Z $. Let $ M_x $, $ M_y $, and $ M_z $ be the masses of the three nuclei X, Y, and Z respectively. Then which of the following relations hold true?

$ (M_x - M_z)<M_y $
$ (M_x - M_y)<M_z $
$ M_x>(M_y + M_z) $
$ M_x<(M_y + M_z) $

View Solution

6.
An astronomical telescope consists of two converging lenses. One of them of large aperture and large focal length is called objective lens and the other one, of smaller focal length and smaller aperture is called the eyepiece. It is used to see distant objects which are not seen clearly with naked eyes. The image formed by the objective lens acts as an object for the eyepiece and the final image produced by the eyepiece is magnified.

NCERT Solutions for class 11 Physics Chapter 9: Mechanical properties of solids

NCERT Solutions for Class 11 Physics Chapter 9

Class 11 Physics Chapter 9 – Concepts Covered

CBSE CLASS XII Related Questions

1.
Derive an expression for the capacitance of a parallel plate capacitor of plate area A and plate separation d with air present between the plates.

5.
Consider the nuclear reaction \( X \to Y + Z \). Let \( M_x \), \( M_y \), and \( M_z \) be the masses of the three nuclei X, Y, and Z respectively. Then which of the following relations hold true?

Similar Physics Concepts

Comments

SUBSCRIBE TO OUR NEWS LETTER

NCERT Solutions for class 11 Physics Chapter 9: Mechanical properties of solids

NCERT Solutions for Class 11 Physics Chapter 9

Class 11 Physics Chapter 9 – Concepts Covered

CBSE CLASS XII Related Questions

1.Derive an expression for the capacitance of a parallel plate capacitor of plate area A and plate separation d with air present between the plates.

5.Consider the nuclear reaction \( X \to Y + Z \). Let \( M_x \), \( M_y \), and \( M_z \) be the masses of the three nuclei X, Y, and Z respectively. Then which of the following relations hold true?

Similar Physics Concepts

Comments

SUBSCRIBE TO OUR NEWS LETTER

1.
Derive an expression for the capacitance of a parallel plate capacitor of plate area A and plate separation d with air present between the plates.

5.
Consider the nuclear reaction \( X \to Y + Z \). Let \( M_x \), \( M_y \), and \( M_z \) be the masses of the three nuclei X, Y, and Z respectively. Then which of the following relations hold true?