# A Simple Guide To Interview Questions On Strength of Materials | 50 Collection Of Questions Commonly Asked in Mechanical Engineering Interview

## Interview Questions On Strength of Materials

This blog post provides top notch interview questions on strength of materials for Mechanical engineering students. Strength of Materials (SOM) is a branch of mechanics that deals with forces that act on bodies. This article contains 30+ Engineering interview questions on various topics of Strength of Materials including classical mechanics, stress strain relations, elasticity, stress analysis, bending & torsion, shearing, deformation, plasticity and fracture mechanics are some of the interesting topics to learn.

## Interview Questions On Strength of Materials and Questions Asked in Mechanical Engineering Interview

Using unique advice and example responses from industry professionals, BlogMech’s interview preparation resources will help you master the most frequently asked interview questions on Strength of Materials. Are you scheduled for a job interview soon? Make your preparations as soon as possible. Here is a collection of frequently asked questions and answers on strength of materials that you may anticipate to encounter.

### 1. Can anybody please provide any link to calculate force required to bend a metal sheet into pipe? or describe how is it calculated?

It depends upon the thickness of sheet and required diameter to be formed from the sheet.

### 2. A bearing designated as 6205 , what is it’s bore diameter:

Generally for bearing bore diameter is 5 times the last number in its designation i.e. for designation 6205, Bore diameter should be 25.

### 3. Where half nut is used

The half nut is used in lathe. In this half nut mechanism, nut is engaged during the thread cutting operation, and it connect carriage and lead screw. It having 2 portion, one half is fixed and one is movable.

### 4. Why the rail is in the form of I-beam? | Interview Questions on Strength of Materials

It’s flexural rigidity is high and it’s cross section consumes low metal.

### 5. Aluminium foil used for cooking food and storage, has one shiny surface and one dull surface. Which surface side be on the outside when the food wrapped for baking and freezing respectively.

1. Shiny side, shiny side
2. Dull side, dull side
3. Shiny side, dull side
4. Dull side, shiny side

Dull side, Shiny side

Reason:

• The shiny surface of foil loses heat through radiation much faster than the dull surface.
• When the food baked shiny surface kept inside, so the heat kept inside and not to leave.
• When the food freeze shiny surface kept outside, so the loss of heat radiated faster which keeps the food in cool.

### 6. What is the difference between pressure and stress? | Interview Questions on Strength of Materials

When the force or load acting on the fluid (pneumatic or hydraulic) per unit area is known as PRESSURE.. Its purely subjected to fluids.

When the force or load acting on the object (solid) within the elastic limit of an object creates internal resistance to resist the apply load. This internal resistance is known as STRAIN per unit area of that object. Its mainly subjected to solids.

### 7. Is there any rake angle in blade? which used to shave the beard ?

It consists of negative rake angle.

### 8. Stress strain diagram for fluid | Interview Questions on Strength of Materials

Parallel line horizontal to stress axis.

### 9. What’s the range of poisson’s ratio of a stable material?

Theoretical values are — -1 to 0.5

Practical values are — 0 to 0.5

### 10. Why 220 V A.C. is more dangerous than 220 V D.C

1. The D.C. attracts
2. Peak voltage for A.C. is much larger
3. The body offers less resistance to A.C.
4. Due to some other reasons

Peak voltage for A.C. is much larger

Reason:

D.C. = 220 volt

A.C. = 1.414 x 220 volt

### 11. What is the difference between limit of proportionality and elastic limit | Interview Questions on Strength of Materials

Up to the limit of proportionality stress is directly proportional to strain, which follows hooke’s law, elastic limit is the limit for elasticity of material.

### 12. In a uniform bar supported at one end in position, the maximum stress under self weight of bar shall occur at

1. Middle of bar
2. Supported end
3. Bottom end
4. None of the above

Supported end

Explanation:

The stress due to self weight is not constant. It increases with the increase of distance from the lower end.

Deflection due to self weight = wl/2AE.

If you consider the bottom end, then Deflection = w/2AE, where l is negligible

If you consider the top end, then Deflection = wl/2AE,

from this above illustrations, we know that deflection is higher in top end. So the stress is more in that region.

### 13. The formulae adopted for IS code is based on | Strength of Materials Interview Questions

1. Straight line formula
2. Rankine’s formula
3. Euler’s formula
4. Secant formula

Secant formula

Explanation:

The proper formula is Secant. Since up to the proportionality limit, we get modulus of elasticity. We get secant modulus of elasticity up to the lower yield point, and tangent modulus above that. IS code has a tangent modulus, as do all the others listed above.

### 14. The maximum hoop stress occurring in a conical tank, when the tank is

1. Full
2. Half
3. Quarter
4. Three quarter

Quarter

Explanation:

Tanks with Conical Bottom

Let θ be semi-vertex angle Consider a point in the conical part at a depth h below the free water surface.

Hoop Stress Fx = Pd/2t

Fx = PR/t

Fx = wbh/(2t cos θ)

### 15. A static load is mounted at the centre of a shaft rotating at uniform angular velocity. This shaft will be designed for

1. The maximum compressive stress (static)
2. The maximum tensile stress (static)
3. The maximum bending moment (static)

Explanation:

Since fatigue is highly sensitive to stress, it is critical to ensure the accuracy of load and stress calculations in fatigue engineering. The magnitude and distribution of stresses induced by applied loads provide information for fatigue analysis as well as expose design flaws.

### 16. A rod of length L and diameter D is subjected to a tensile load P. Which of the following is sufficient to calculate the resulting change in diameter?

1. Young’s modulus
2. Shear modulus
3. Poisson’s ratio
4. Both Young’s modulus and shear modulus

Both Young’s modulus and Shear modulus

Explanation:

Young’s modulus is used to measure longitudinal strain, and poisson’s ratio is used to calculate transverse strain. The equation E = 2G(1+μ) is used to calculate shear modulus.

### 17. A test specimen is stressed slightly beyond the yield point and then unloaded. Its yield strength will | SOM Interview Questions

1. Decrease
2. Increase
3. Remains same
4. Becomes equal to ultimate tensile strength

Increase

Explanation:

### 18. If the value of Poisson’s ratio is zero, then it means that

1. The material is rigid
2. The material is perfectly plastic
3. There is no longitudinal strain in the material
4. The longitudinal strain in the material is infinite

The material is rigid

### 19. When a nut is tightened by placing a washer below it, the bolt will be subjected to | Interview Questions on Strength of Materials

1. Compression only
2. Tension only
3. Shear only
4. Compression and Shear

Tension

### 20. During tensile-testing of a specimen using a universal testing machine, the parameters actually measured include | Strength of Materials Interview Questions

1. True stress and True strain
2. Poisson’s ratio and Young’s modulus
3. Engineering stress and Engineering strain

### 21. The main alloying elements in high speed steel in order of increasing proportions are

4. Tungsten, Chromium, Titanium

### 22. Constituents of ceramics are oxides of different material, which are

1. Cold mixed to make ceramic pallets
2. Ground, sintered and palleted to make ready ceramics
3. Ground, washed with acid, heated and cooled
4. Ground, sintered, palleted and after calcining cooled in oxygen

Ground, sintered and palleted to make ready ceramics

### 23. A machinist desires to turn a round steel stock of outside diameter 100 mm at 1000 RPM. The material has tensile strength of 75 kg/mm2. The depth of cut chosen is 3 mm at a feed rate of 0.3 mm/rev. Which one of the following tool materials will be suitable for machining the component under the specified cutting conditions?

1. Sintered carbides
2. Ceramic
3. HSS
4. Diamond

Ceramic

1. Alumina
2. Porcelain
3. Whisker
4. Pyrosil

Pyrosil

### 25. At room temperature, which one of the following is the correct sequence of increasing hardness of the tool materials?

1. Cast alloys-HSS-Ceramic-Carbide
2. HSS-Cast alloy-Ceramic-Carbide
3. HSS-Cast alloy-Carbide-Ceramic
4. Cast alloy-HSS-Carbide-Ceramic

Cast alloy-HSS-Carbide-Ceramic

### 26. The coating materials for coated carbide tools, includes | SOM Interview Questions

1. TiC, TiN and NaCN
2. TiC and TiN
3. TiN and NaCN
4. TiC and NaCN

TiC and TiN

### 27. The cutting tool material required to sustain high temperature is

1. High carbon steel alloys
2. Composite of lead and steel
3. Cermet (Metal ceramic composites)
4. Alloy of steel, zinc, and tungsten

Cermet

### 28. Which one of the following is not a synthetic abrasive material? | Strength of Materials Interview Questions

1. Silicon Carbide
2. Aluminium Oxide
3. Titanium Nitride
4. Cubic Boron Nitride