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# Test: Elastic Moduli

## 10 Questions MCQ Test Physics Class 11 | Test: Elastic Moduli

Description
This mock test of Test: Elastic Moduli for JEE helps you for every JEE entrance exam. This contains 10 Multiple Choice Questions for JEE Test: Elastic Moduli (mcq) to study with solutions a complete question bank. The solved questions answers in this Test: Elastic Moduli quiz give you a good mix of easy questions and tough questions. JEE students definitely take this Test: Elastic Moduli exercise for a better result in the exam. You can find other Test: Elastic Moduli extra questions, long questions & short questions for JEE on EduRev as well by searching above.
QUESTION: 1

Solution:
QUESTION: 2

### The length of the wire is increased by 1 mm on the application of a given load. In a wire of the same material but of length and radius twice that of the first, on application of the same force, extension produced is

Solution:

Young's Modulus of elasticity =stress/strain
Y= [F/a/△l/l] ​ or Y= [Fl​/a△l]
or △l= [Fl/aY] ​= Fl​/ πr2Y
In the given problem, △l∝ l​/ r2
When both l and r are doubled, △l is halved.

QUESTION: 3

### Young’s modulus is defined as the ratio of longitudinal stress to longitudinal strain. Which of the following is the unit of Young’s modulus?

Solution:

Stress = Force per area and strain is unit less.
Therefore in CGS units dyne per cm square.
Hence A is correct.

QUESTION: 4

The volume of a spherical body is decreased by 10-3% when it is subjected to pressure of 40 atmospheres. Find the bulk modulus of body.
(1 atm = 1.01 x 103 N/m2).

Solution:

We know that magnitude of bulk modulus
K=[P/(dV/V)]
Now, percentage change in volume is. 10-3 %
Therefore, (dV/V)x100=10-3
So, dV/V=10-5
Hence, k is,
K=40atm/10-5=40x1.01x105 /10-5 =4.04x1011 N/m

QUESTION: 5

The materials which have the same elastic properties in all directions are called __________.

Solution:

Same elastic properties in all direction is called the homogenity of a material.

QUESTION: 6

How does the modulus of elasticity change with temperature?

Solution:

As the temperature increases, the inter-atomic distance also increases. So, it results in an increase in the area (stress = force /area). As the area increases stress decreases, this results in a decrease in Young's modulus.

QUESTION: 7

What type of stress is produced in a body when the deforming force produces sheer strain?

Solution:

When the direction of the deforming force or external force is parallel to the cross-sectional area, the stress experienced by the object is called shearing stress or tangential stress. This results in the change in the shape of the body.

QUESTION: 8

Modulus of rigidity is defined as the

Solution:

Modulus of rigidity is defined as the ratio of Shear stress to shear strain.

QUESTION: 9

Which of the following represents Hooke’s Law?

Solution:

E=stress/strain
Strain x E= Stress

QUESTION: 10

An iron bar of length l cm and cross section A cm2 is pulled by a force F dynes from the ends so as to produce an elongation l cm. Which of the following statements is correct?

Solution:

F =AYΔl/L
Δl = FL/AY