# Balbharati solutions for Physics 11th Standard Maharashtra State Board chapter 6 - Mechanical Properties of Solids [Latest edition]

## Chapter 6: Mechanical Properties of Solids

Exercises
Exercises [Pages 112 - 113]

### Balbharati solutions for Physics 11th Standard Maharashtra State Board Chapter 6 Mechanical Properties of Solids Exercises [Pages 112 - 113]

Exercises | Q 1. (i) | Page 112

Change in dimensions is known as _________.

• deformation

• formation

• contraction

• strain

Exercises | Q 1. (ii) | Page 112

The point on the stress-strain curve at which strain begins to increase even without increase in stress is called ________

• elastic point

• yield point

• breaking point

• neck point

Exercises | Q 1. (iii) | Page 112

Strain energy of a stretched wire is 18 × 10-3 J and strain energy per unit volume of the same wire and same cross-section is 6×10-3 J/m3. Its volume will be _________.

• 3cm3

• 3 m3

• 6 m3

• 6 cm3

Exercises | Q 1. (iv) | Page 112

________ is the property of a material which enables it to resist plastic deformation.

• elasticity

• plasticity

• hardness

• ductility

Exercises | Q 1. (v) | Page 112

The ability of a material to resist fracturing when force is applied to it, is called ______.

• toughness

• hardness

• elasticity

• plasticity

Exercises | Q 2. (i) | Page 112

Define elasticity.

Exercises | Q 2. (ii) | Page 112

What do you mean by deformation?

Exercises | Q 2. (iii) | Page 112

State the SI unit and dimensions of stress.

Exercises | Q 2. (iv) | Page 112

Define strain.

Exercises | Q 2. (v) | Page 112

What is Young’s modulus of a rigid body?

Exercises | Q 2. (vi) | Page 112

Why bridges are unsafe after very long use?

Exercises | Q 2. (vii) | Page 112

How should be a force applied on a body to produce shearing stress?

Exercises | Q 2. (viii) | Page 112

State the condition under which Hooke’s law holds good.

Exercises | Q 2. (ix) | Page 112

Define Poisson’s ratio.

Exercises | Q 2. (x) | Page 112

What is an elastomer?

Exercises | Q 2. (xi) | Page 112

What do you mean by elastic hysteresis?

Exercises | Q 2. (xii) | Page 112

State the names of the hardest material and the softest material.

Exercises | Q 2. (xiii) | Page 112

Define friction.

Exercises | Q 2. (xiv) | Page 112

Why force of static friction is known as ‘self-adjusting force’?

Exercises | Q 2. (xv) | Page 112

Name two factors on which the coefficient of friction depends.

Exercises | Q 3. (i) | Page 112

Distinguish between elasticity and plasticity.

Exercises | Q 3. (ii) | Page 112

State any four methods to reduce friction.

Exercises | Q 3. (iii) | Page 112

What is rolling friction? How does it arise?

Exercises | Q 3. (iv) | Page 112

Explain how lubricants help in reducing friction.

Exercises | Q 3. (v) | Page 112

State the laws of static friction.

Exercises | Q 3. (vi) | Page 112

State the laws of kinetic friction.

Exercises | Q 3. (vii) | Page 112

Exercises | Q 3. (viii) | Page 112

Exercises | Q 3. (ix) | Page 112

What do you mean by brittle substance? Give any two examples.

Exercises | Q 4. (i) | Page 112

Distinguish between Young’s modulus, bulk modulus, and modulus of rigidity.

Exercises | Q 4. (ii) | Page 112

Define stress and strain. What are their different types?

Exercises | Q 4. (iii) | Page 112

What is Young’s modulus?

Exercises | Q 4. (iii) | Page 112

Describe an experiment to find out Young’s modulus of the material in the form of a long string wire.

Exercises | Q 4. (iv) | Page 112

Derive an expression for strain energy per unit volume of the material of a wire.

Exercises | Q 4. (v) | Page 112

Define friction.

Exercises | Q 4. (v) | Page 112

Define coefficient of static friction and coefficient of kinetic friction. Give the necessary formula for each.

Exercises | Q 4. (vi) | Page 112

State Hooke’s law.

Exercises | Q 4. (vi) | Page 112

Draw a labelled graph of tensile stress against tensile strain for a metal wire up to the breaking point. In this graph show the region in which Hooke’s law is obeyed.

Exercises | Q 5. (i) | Page 113

Calculate the coefficient of static friction for an object of mass 50 kg placed on a horizontal table pulled by attaching a spring balance. The force is increased gradually, it is observed that the object just moves when spring balance shows 50 N.

Exercises | Q 5. (ii) | Page 113

A block of mass 37 kg rests on a rough horizontal plane having coefficient of static friction 0.3. Find out the least force required to just move the block horizontally.

Exercises | Q 5. (iii) | Page 113

A body of mass 37 kg rests on a rough horizontal surface. The minimum horizontal force required to just start the motion is 68.5 N. In order to keep the body moving with constant velocity, a force of 43 N is needed. What is the value of
i. coefficient of static friction? and
ii. coefficient of kinetic friction?

Exercises | Q 5. (iv) | Page 113

A wire gets stretched by 4 mm due to a certain load. If the same load is applied to a wire of same material with half the length and double the diameter of the first wire, what will be the change in its length?

Exercises | Q 5. (v) | Page 113

Calculate the work done in stretching a steel wire of length 2 m and cross-sectional area 0.0225 mm2 when a load of 100 N is slowly applied to its free end. (Young’s modulus of steel = 2 × 1011 N/m2)

Exercises | Q 5. (vi) | Page 113

A solid metal sphere of volume 0.31 m3 is dropped in an ocean where water pressure is 2 × 107 N/m2. Calculate change in volume of the sphere if the bulk modulus of the metal is 6.1 × 1010 N/m2.

Exercises | Q 5. (vii) | Page 113

A wire of mild steel having an initial length 1.5 m and diameter 0.60 mm gets extended by 6.3 mm when a certain force is applied to it. If Young’s modulus of mild steel is 2.1 × 1011 N/m2, calculate force applied.

Exercises | Q 5. (viii) | Page 113

A composite wire is prepared by joining a tungsten wire and steel wire end to end. Both the wires are of the same length and the same area of cross-section. If this composite wire is suspended to a rigid support and a force is applied to its free end, it gets extended by 3.25 mm. Calculate the increase in the length of tungsten wire and steel wire separately.
(YTungsten = 4.1 × 1011 Pa. YSteel = 2 × 1011 Pa)

Exercises | Q 5. (ix) | Page 113

A steel wire having a cross-sectional area of 1.2 mm2 is stretched by a force of 120 N. If a lateral strain of 1.455 × 10-4 is produced in the wire, calculate the Poisson’s ratio.
(Given: YSteel = 2 × 1011 N/m2)

Exercises | Q 5. (x) | Page 113

A telephone wire 125 m long and 1 mm in radius is stretched to a length 125.25 m when a force of 800 N is applied. What is the value of Young’s modulus for the material of wire?

Exercises | Q 5. (xi) | Page 113

A rubber band originally 30 cm long is stretched to a length of 32 cm by a certain load. What is the strain produced?

Exercises | Q 5. (xii) | Page 113

What is the stress in a wire which is 50m long and 0.01 cm2 in cross-section, if the wire bears a load of 100 kg?

Exercises | Q 5. (xiii) | Page 113

What is the strain in a wire cable of the original length 50 m whose length increases by 2.5 cm when a load is lifted?

Exercises

## Balbharati solutions for Physics 11th Standard Maharashtra State Board chapter 6 - Mechanical Properties of Solids

Balbharati solutions for Physics 11th Standard Maharashtra State Board chapter 6 (Mechanical Properties of Solids) include all questions with solution and detail explanation. This will clear students doubts about any question and improve application skills while preparing for board exams. The detailed, step-by-step solutions will help you understand the concepts better and clear your confusions, if any. Shaalaa.com has the Maharashtra State Board Physics 11th Standard Maharashtra State Board solutions in a manner that help students grasp basic concepts better and faster.

Further, we at Shaalaa.com provide such solutions so that students can prepare for written exams. Balbharati textbook solutions can be a core help for self-study and acts as a perfect self-help guidance for students.

Concepts covered in Physics 11th Standard Maharashtra State Board chapter 6 Mechanical Properties of Solids are Introduction to Mechanical Properties of Solids, Elastic Behavior of Solids, Stress and Strain, Hooke’s Law, Elastic Modulus, Stress-strain Curve, Strain Energy, Hardness, Friction in Solids.

Using Balbharati 11th solutions Mechanical Properties of Solids exercise by students are an easy way to prepare for the exams, as they involve solutions arranged chapter-wise also page wise. The questions involved in Balbharati Solutions are important questions that can be asked in the final exam. Maximum students of Maharashtra State Board 11th prefer Balbharati Textbook Solutions to score more in exam.

Get the free view of chapter 6 Mechanical Properties of Solids 11th extra questions for Physics 11th Standard Maharashtra State Board and can use Shaalaa.com to keep it handy for your exam preparation