Design Of Machine Elements Set 4

Mechanical Engineering

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This set of Design of Machine Elements Multiple Choice Questions & Answers (MCQs) focuses on Design Of Machine Elements Set 4

Q1 | Riveting is not recommended for aluminium alloys.
  • true
  • false
Answer: false
Explaination:
aluminium alloys have poor weldability and hence riveting is preferred.
Q2 | In joining steel plate and asbestos, welding is preferred over riveting.
  • true
  • false
Answer: false
Explaination:
riveting is preferred in joining heterogeneous materials.
Q3 | Quality checking of riveted joint is much expensive than that of welded joint.
  • true
  • false
Answer: false
Explaination:
in welding, inspections like radiographic inspections are quite costly.
Q4 | In which of the following bonding theory, water molecules break down to form H+ and OH- ions?
  • electrostatic bonding theory
  • hot strength theory
  • surface tension theory
  • block and wedge theory
Answer: electrostatic bonding theory
Explaination:
in electrostatic bonding theory, water is mixed in clay and sand grains, these water molecules then break into h+ ions and oh– ions.
Q5 | What does the clay particle absorb in electrostatic bonding theory?
  • complete water
  • h+ ions
  • oh–ions
  • sand grains
Answer: oh–ions
Explaination:
the oh– ions are basically the base ions. the clay particles in electrostatic bonding theory, absorb the oh– ions because of the not satisfied valence bond.
Q6 | For bonding action of clays, what is the amount of water needed?
  • 1.5%-8%
  • 3.5%-11%
  • 4.5%-12%
  • 5.5%-13%
Answer: 1.5%-8%
Explaination:
for the bonding action of the clays, water is needed, which activates the
Q7 | What is the amount of sea coal needed in cast irons for large green casting moulding sands?
  • 10%
  • 15%
  • 20%
  • 25%
Answer: 10%
Explaination:
sea coal otherwise is used in small numbers for binding. sea coal is used for surface appearance improvement. it is used about 10% in cast iron moulding sands for large green casting sands.
Q8 | Pitch maybe used up to what percent?
  • 1%
  • 2%
  • 3%
  • 4%
Answer: 2%
Explaination:
pitch distillation of soft coals plays a vital role in bonding theory. pitch is used for getting a good surface finish on iron casts. these pitches generally are used up to be to 2%.
Q9 | Which of the following increases the dry strength of the sand?
  • iron oxides
  • fuel oils
  • cereals
  • dextrin and molasses
Answer: dextrin and molasses
Explaination:
dextrin and molasses are used for increasing the dry strength of the sand, which add hardness to the mould.
Q10 | Cereals improve flowability and lower collapsibility.
  • true
  • false
Answer: false
Explaination:
cereals do not improve flowability, as a matter of fact, it reduces it, and, cereals are not known to reduce or not the collapsibility, in fact it is known to improve it.
Q11 | How much should fuel oil be added to increase the moulding ability of sand?
  • 0.01% – 0.1%
  • 0.02% – 0.2%
  • 0.03% – 0.3%
  • 0.04% – 0.4%
Answer: 0.01% – 0.1%
Explaination:
fuel oils are known to have great properties in them. fuel oils are helpful in adding to the increase of the moulding
Q12 | Which of the following function can the spring perform?
  • store energy
  • absorb shock
  • measure force
  • all of the mentioned
Answer: all of the mentioned
Explaination:
spring can easily perform all the listed functions.
Q13 | The helix angle is very small about 2⁰. The spring is open coiled spring.
  • yes
  • it is closed coiled spring
  • that small angle isn’t possible
  • none of the listed
Answer: it is closed coiled spring
Explaination:
when the helix angle is small, the plane containing each coil is almost at right angles and hence it is called closed coiled spring.
Q14 | The helical spring ad wire of helical torsion spring, both are subjected to torsional shear stresses.
  • true
  • false
  • topic 4.1 various types of springs, optimization of helical springs - rubber springs
Answer: false
Explaination:
the wire of helical torsion sprig is subjected to bending stresses.
Q15 | Multi leaf springs are not recommended for automobile and rail road suspensions.
  • true
  • false
Answer: false
Explaination:
they are highly used in automobile and rail road suspensions.
Q16 | The spring index is the ratio of wire diameter to mean coil diameter.
  • true
  • false
Answer: true
Explaination:
it is the ratio of mean coil diameter to wire diameter.
Q17 | If spring index=2.5, what can be concluded about stresses in the wire?
  • they are high
  • they are negligible
  • they are moderate
  • cannot be determined
Answer: they are high
Explaination:
if indexis <3 then stresses are high due to curvature effect.
Q18 | A spring with index=15 is prone to buckling.
  • true
  • false
Answer: true
Explaination:
due to large variation, such a spring is prone to buckling.
Q19 | If number of coils are 8 and wire diameter of spring 3mm, then solid length is given by?
  • none of the listed
  • 27mm
  • 24mm
  • 21mm
Answer: 24mm
Explaination:
solid length=8×3.
Q20 | Compressed length is smaller than the solid length.
  • true
  • false
Answer: false
Explaination:
compressed is length of spring under maximum compressive force. there is some gap between the coils under maximum load.
Q21 | Pitch of coil is defined as axial distance in compressed state of the coil.
  • yes
  • it is measured in uncompressed state
  • it is same in uncompressed or compressed state
  • none of the listed
Answer: it is measured in uncompressed state
Explaination:
pitch is measured in uncompressed state.
Q22 | Active and inactive, both types of coils support the load although both don’t participate in spring action.
  • active coils don’t support the load
  • inactive coils don’t support the load
  • both active and inactive don’t support the load
  • both active and inactive support the load
Answer: inactive coils don’t support the load
Explaination:
inactive coils don’t support the load.
Q23 | The maximum fluctuation of speed is the
  • difference of minimum fluctuation of speed and the mean speed
  • difference of the maximum and minimum speeds
  • sum of the maximum and minimum speeds
  • variations of speed above and below the mean resisting torque line
Answer: difference of the maximum and minimum speeds
Explaination:
the difference between the maximum and minimum speeds during a cycle is called the maximum fluctuation of speed.
Q24 | In a turning moment diagram, the variations of energy above and below the mean resisting torque line is called
  • fluctuation of energy
  • maximum fluctuation of energy
  • coefficient of fluctuation of energy
  • none of the mentioned
Answer: fluctuation of energy
Explaination:
the fluctuation of energy may be determined by the turning moment diagram for one complete cycle of operation.the variations of energy above and below the mean resisting torque line are called fluctuation of energy.
Q25 | The ratio of the maximum fluctuation of energy to the ……. is called coefficient of fluctuation of energy.
  • minimum fluctuation of energy
  • workdone per cycle
  • maximum fluctuation of energy
  • none of the mentioned
Answer: workdone per cycle
Explaination:
the difference between the maximum and the minimum energies is known as maximum fluctuation of energy.
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