NCERT Solution (Class 11) > Physics Chapter 9 Mechanical Properties Of Solids
NCERT Solution Class 11 Physics Chapter 9 Mechanical Properties Of Solids: National Council of Educational Research and Training Class 11 Physics Chapter 9 Solution – Mechanical Properties Of Solids. Free PDF Download facility available at our website.
Board |
NCERT |
Class |
11 |
Subject |
Physics |
Chapter |
9 |
Chapter Name |
Mechanical Properties Of Solids |
Topic |
Exercise Solution |
Mechanical Properties Of Solids Chapter all Questions and Numericals Solution
9.1)
9.2) show the strain-stress curve for a given material. What are (a) Young’s modulus and (b) approximate yield strength for this material?
ANSWER-
(a)We know that,
Young’s modulus( Y) = stress/strain
From graph ,
At strain = 0.002 we have stress = 150 x 106 N/m2
Y = 150 x 106/ 0.002
∴ Y = 7.5 x 1010 N/m2.
(b)The yield strength of a material is the maximum stress that the material can withstand within elastic limit.
From graph it is clear that maximum stress is 300 x 106 N/m2. Hence The yield strength of a material is 300 x 106 N/m2.
9.3) The stress-strain graphs for materials A and B are shown in Fig. 9.12. Fig. 9.12 The graphs are drawn to the same scale. (a) Which of the materials has the greater Young’s modulus? (b) Which of the two is the stronger material?
ANSWER-
ANSWER-
(a)We know that,
Young’s modulus( Y) = stress/strain
That is Young’s modulus is the slope of the stress – strain curve. From graphs we can observe that slope of graph A is more than graph B Hence Young’s modulus of material A is more than Young’s modulus of material B.
(b)Stronger material means the material which withstands maximum stress before fracture. From given stress- strain curve we observe that material A is stronger than material B.
9.4) Read the following two statements below carefully and state, with reasons, if it is true or false. (a) The Young’s modulus of rubber is greater than that of steel; (b) The stretching of a coil is determined by its shear modulus.
ANSWER-
(a)False. We know that,
Young’s modulus( Y) = stress/strain
Which means stress is inversally proportional to strain at given stress by observation we can conclude that with same force rubber extension is more than extension in steel means rubber shows more strain than steel hence rubber has less young’s modulus than steel.
(b) to answer this question one should know about shear modulus. Shear modulus is change in the shape of a body. While The stretching of a coil results into change in its shape. Hence the stretching of a coil is determined by its shear modulus.
9.5)
9.6)
9.7)
9.8)
9.9)
9.12)
In case you are missed :- NCERT Solution for Mechanical Properties Of Fluids
9.13)
9.14)
Additional Exercises
9.17)
9.18)
9.19)
9.21)
In case you are missed :- NCERT Solution for Thermal Properties Of Matter