Unit 1 st

1. Which of the following material has the maximum ductility?

(i) Mild steel (b) Copper

(ii) Zinc (d) Aluminium

2. According to Indian standard specifications, a grey cast iron designated by ‘FG 200’

means that the

(i) carbon content is 2%

(ii) maximum compressive strength is 200 N/mm2

(iii) minimum tensile strength is 200 N/mm2

(iv) maximum shear strength is 200 N/mm2

3. According to Indian standard specifications, a plain carbon steel designated by 40C8

means that

(i) carbon content is 0.04 per cent and manganese is 0.08 per cent

(ii) carbon content is 0.4 per cent and manganese is 0.8 per cent

(iii) carbon content is 0.35 to 0.45 per cent and manganese is 0.60 to 0.90 per cent

(iv) carbon content is 0.60 to 0.80 per cent and manganese is 0.8 to 1.2 per cent

4. The material commonly used for machine tool bodies is

(i) mild steel (b) aluminium

(ii) brass (d) cast iron

5. The material commonly used for crane hooks is

(i) cast iron (b) wrought iron

(ii) mild steel (d) aluminium

6. Shock resistance of steel is increased by adding

(i) nickel (b) chromium

(ii) nickel and chromium (d) sulphur, lead and phosphorus

7. The steel widely used for motor car crankshafts is

(i) nickel steel (b) chrome steel

(ii) nickel-chrome steel (d) silicon steel

8. A steel with 0.8 per cent carbon is known as

(i) eutectoid steel (b) hypereutectoid steel

(ii) hypoeutectoid steel (d) none of these

9. 18/8 steel contains

(i) 18 per cent nickel and 8 per cent chromium

(ii) 18 per cent chromium and 8 per cent nickel

(iii) 18 per cent nickel and 8 per cent vanadium

(iv) 18 per cent vanadium and 8 per cent nickel

10. Ball bearing are usually made from

(i) low carbon steel (b) high carbon steel

(ii) medium carbon steel (d) high speed steel

11. The process which improves the machinability of steels, but lower the hardness and

tensile strength

12. is

(i) normalising (b) full annealing

(ii) process annealing (d) spheroidising

13. The metal suitable for bearings subjected to heavy loads is

(i) silicon bronze (b) white metal

(ii) monel metal (d) phosphor bronze

14. The metal suitable for bearings subjected to light loads is

(i) silicon bronze (b) white metal

(ii) monel metal (d) phosphor bronze

15. Thermoplastic materials are those materials which

(i) are formed into shape under heat and pressure and results in a permanently

hard product

(ii) do not become hard with the application of heat and pressure

(iii) are flexible and can withstand considerable wear under suitable conditions

(iv) are used as a friction lining for clutches and brakes

16. Define the following properties of a material :

(i) Ductility, (ii) Toughness, (iii) Hardness, and (iv) Creep.

17. Give the composition of 35 Mn 2 Mo 45 steel

18. Which heat treatment process increases the yield strength:

19. Normalising; 2. Hardening; and 3. Tempering.

20. which property is related to the time

(i) Ductility, (ii) Toughness, (iii) Hardness, and (iv) Creep.

21. letter XT is used for

a. high speed tool steel b. spring steel c. alloy steel

22. which makes the steel brittle

a. Nickel b. sulphur c. phosphorous d. silicon

23. The Poisson’s ratio for steel varies from

(a) 0.21 to 0.25 (b) 0.25 to 0.33 (c) 0.33 to 0.38 (d) 0.38 to 0.45

UNIT 4 TH

1. A spring used to absorb shocks and vibrations is

(a) closely-coiled helical spring (b) open-coiled helical spring

(c) conical spring (d) torsion spring

2. The spring mostly used in gramophones is

(a) helical spring (b) conical spring

(c) laminated spring (d) flat spiral spring

3. Which of the following spring is used in a mechanical wrist watch?

(a) Helical compression spring (b) Spiral spring

(c) Torsion spring (d) Bellevile spring

4. When a helical compression spring is subjected to an axial compressive load, the stress

induced in the wire is

(a) tensile stress (b) compressive stress

(c) shear stress (d) bending stress

6. When helical compression spring is cut into halves, the stiffness of the resulting spring will be

(a) same (b) double

(c) one-half (d) one-fourth

8. When two concentric coil springs made of the same material, having same length and

compressed equally by an axial load, the load shared by the two springs will be ............ to the

square of the diameters of the wires of the two springs.

(a) directly proportional (b) inversely proportional

(c) equal to

9. A leaf spring in automobiles is used

(a) to apply forces (b) to measure forces

(c) to absorb shocks (d) to store strain energy

10. In leaf springs, the longest leaf is known as

(a) lower leaf (b) master leaf

(c) upper leaf (d) none of these

Which of the following screw thread is adopted for power transmission in either direction?

(a) Acme threads (b) Square threads

(c) Buttress threads (d) Multiple threads

2. Multiple threads are used to secure

(a) low efficiency (b) high efficiency

(c) high load lifting capacity (d) high mechanical advantage

3. Screws used for power transmission should have

(a) low efficiency (b) high efficiency

(c) very fine threads (d) strong teeth

4. To ensure self locking in a screw jack, it is essential that the helix angle is

(a) larger than friction angle (b) smaller than friction angle

(c) equal to friction angle (d) such as to give maximum efficiency in lifting

5. A screw is said to be self locking screw, if its efficiency is

(a) less than 50% (b) more than 50%

(c) equal to 50% (d) none of these

6. A screw is said to be over hauling screw, if its efficiency is

(a) less than 50% (b) more than 50%

(c) equal to 50% (d) none of these

7. While designing a screw in a screw jack against buckling failure, the end conditions for the

screw are taken as

(a) both ends fixed (b) both ends hinged

(c) one end fixed and other end hinged (d) one end fixed and other end free.

8. The load cup of a screw jack is made separate from the head of the spindle to

(a) enhance the load carrying capacity of the jack

(b) reduce the effort needed for lifting the working load

(c) reduce the value of frictional torque required to be countered for lifting the load

(d) prevent the rotation of load being lifted

Unit 2 nd

1. When a machine member is subjected to torsion, the torsional shear stress set up in the

member is

(a) zero at both the centroidal axis and outer surface of the member

(b) Maximum at both the centroidal axis and outer surface of the member

(c) zero at the centroidal axis and maximum at the outer surface of the member

(d) none of the above

2. The torsional shear stress on any cross-section normal to the axis is ......... the distance from

the centre of the axis.

(a) directly proportional to (b) inversely proportional to

3. The neutral axis of a beam is subjected to

(a) zero stress (b) maximum tensile stress

(c) maximum compressive stress (d) maximum shear stress

4. At the neutral axis of a beam,

(a) the layers are subjected to maximum bending stress

(b) the layers are subjected to tension (c) the layers are subjected to compression

(d) the layers do not undergo any strain

5. The bending stress in a curved beam is

(a) zero at the centroidal axis (b) zero at the point other than centroidal axis

(c) maximum at the neutral axis (d) none of the above

6. The maximum bending stress, in a curved beam having symmetrical section, always occur, at

the

(a) centroidal axis (b) neutral axis

(c) inside fibre (d) outside fibre

7. Rankine’s theory is used for

(a) brittle materials (b) ductile materials

(c) elastic materials (d) plastic materials

8. Guest’s theory is used for

(a) brittle materials (b) ductile materials

(c) elastic materials (d) plastic materials

9. At the neutral axis of a beam, the shear stress is

(a) zero (b) maximum

(c) minimum

Variable stresses:

1. The stress which vary from a minimum value to a maximum value of the same nature

(i.e. tensile or

compressive) is called

(a) repeated stress (b) yield stress

(c) fluctuating stress (d) alternating stress

2. The endurance or fatigue limit is defined as the maximum value of the stress which a polished

standard specimen can withstand without failure, for infinite number of cycles, when subjected

to

(a) static load (b) dynamic load

(c) static as well as dynamic load (d) completely reversed load

3. Failure of a material is called fatigue when it fails

(a) at the elastic limit (b) below the elastic limit

(c) at the yield point (d) below the yield point

4. The resistance to fatigue of a material is measured by

(a) elastic limit (b) Young's modulus

(c) ultimate tensile strength (d) endurance limit

5. The yield point in static loading is ............... as compared to fatigue loading.

(a) higher (b) lower (c) same

6. Factor of safety for fatigue loading is the ratio of

(a) elastic limit to the working stress

(b) Young's modulus to the ultimate tensile strength

(c) endurance limit to the working stress

(d) elastic limit to the yield point

7. When a material is subjected to fatigue loading, the ratio of the endurance limit to the ultimate

tensile strength is

(a) 0.20 (b) 0.35

(c) 0.50 (d) 0.65

8. The ratio of endurance limit in shear to the endurance limit in flexure is

(a) 0.25 (b) 0.40

(c) 0.55 (d) 0.70

9. If the size of a standard specimen for a fatigue testing machine is increased, the endurance

limit for the material will

(a) have same value as that of standard specimen (b) increase (c) decrease

10. The residential compressive stress by way of surface treatment of a machine member

subjected to fatigue loading

(a) improves the fatigue life (b) deteriorates the fatigue life

(c) does not affect the fatigue life (d) immediately fractures the specimen

11. The surface finish factor for a mirror polished material is

(a) 0.45 (b) 0.65

(c) 0.85 (d) 1

12. Stress concentration factor is defined as the ratio of

(a) maximum stress to the endurance limit (b) nominal stress to the endurance limit

(c) maximum stress to the nominal stress (d) nominal stress to the maximum stress

13. In static loading, stress concentration is more serious in

(a) brittle materials (b) ductile materials

(c) brittle as well as ductile materials (d) elastic materials

14. In cyclic loading, stress concentration is more serious in

(a) brittle materials (b) ductile materials

(c) brittle as well as ductile materials (d) elastic materials

Riveted joint :

1. A rivet is specified by

(a) shank diameter (b) length of rivet

(c) type of head (d) length of tail

2. The diameter of the rivet hole is usually ............ the nominal diameter of the rivet.

(a) equal to (b) less than (c) more than

3. The rivet head used for boiler plate riveting is usually

(a) snap head (b) pan head

(c) counter sunk head (d) conical head

4. A line joining the centres of rivets and parallel to the edge of the plate is known as

(a) back pitch (b) marginal pitch

(c) gauge line (d) pitch line

5. The centre to centre distance between two consecutive rivets in a row, is called

(a) margin (b) pitch

(c) back pitch (d) diagonal pitch

6. The objective of caulking in a riveted joint is to make the joint

(a) free from corrosion (b) stronger in tension

(c) free from stresses (d) leak-proof

7. . A lap joint is always in .....shear.

(a) single (b) double

8. A double strap butt joint (with equal straps) is

(a) always in single shear (b) always in double shear

(c) either in single shear or double shear (d) any one of these

9. Which of the following riveted butt joints with double straps should have the highest

efficiency as per Indian Boiler Regulations?

(a) Single riveted (b) Double riveted

(c) Triple riveted (d) Quadruple riveted

10. If the tearing efficiency of a riveted joint is 50%, then ratio of diameter of rivet hole to the

pitch of rivets is

(a) 0.20 (b) 0.30

(c) 0.50 (d) 0.60

Unit 3 rd

Keys & couplings:

The taper on a rectangular sunk key is

(a) 1 in 16 (b) 1 in 32

(c) 1 in 48 (d) 1 in 100

2. The usual proportion for the width of key is

(a) d/8 (b) d/6

(c) d/4 (d) d/2

where d = Diameter of shaft.

3. When a pulley or other mating piece is required to slide along the shaft, a ................ sunk key

is used.

(a) rectangular (b) square (c) parallel

4. A key made from a cylindrical disc having segmental cross-section, is known as

(a) feather key (b) gib head key

(c) woodruff key (d) flat saddle key

5. A feather key is generally

(a) loose in shaft and tight in hub (b) tight in shaft and loose in hub

(c) tight in both shaft and hub (d) loose in both shaft and hub.

6. The type of stresses developed in the key is/are

(a) shear stress alone (b) bearing stress alone

(c) both shear and bearing stresses (d) shearing, bearing and bending stresses

7. For a square key made of mild steel, the shear and crushing strengths are related as

(a) shear strength = crushing strength (b) shear strength > crushing strength

(c) shear strength < crushing strength (d) none of the above

8. A keyway lowers

(a) the strength of the shaft (b) the rigidity of the shaft

(c) both the strength and rigidity of the shaft (d) the ductility of the material of the shaft

9. The sleeve or muff coupling is designed as a

(a) thin cylinder (b) thick cylinder

(c) solid shaft (d) hollow shaft

10. Oldham coupling is used to connect two shafts

(a) which are perfectly aligned (b) which are not in exact alignment

(c) which have lateral misalignment (d) whose axes intersect at a small angle

Shafts:

1. The standard length of the shaft is

(a) 5 m (b) 6 m

(c) 7 m (d) all of these

2. Two shafts A and B are made of the same material. The diameter of the shaft A is twice as that

of shaft

B. The power transmitted by the shaft A will be ........... of shaft B.

(a) twice (b) four times

(c) eight times (d) sixteen times

3. Two shafts will have equal strength, if

(a) diameter of both the shafts is same

(b) angle of twist of both the shafts is same

(c) material of both the shafts is same

(d) twisting moment of both the shafts is same

A transmission shaft subjected to bending loads must be designed on the basis of

(a) maximum normal stress theory

(b) maximum shear stress theory

(c) maximum normal stress and maximum shear stress theories

(d) fatigue strength

6. Which of the following loading is considered for the design of axles ?

(a) Bending moment only

(b) Twisting moment only

(c) Combined bending moment and torsion

(d) Combined action of bending moment, twisting moment and axial thrust

7. The maximum shear stress theory is used for

(a) brittle materials (b) ductile materials

(c) plastic materials (d) non-ferrous materials

8. The maximum normal stress theory is used for

(a) brittle materials (b) ductile materials

(c) plastic materials (d) non-ferrous materials

9. The design of shafts made of brittle materials is based on

(a) Guest’s theory (b) Rankine’s theory

(c) St. Venant’s theory (d) Von Mises Theory