Quiz: Mechanical engineering 10 April 2020

Quiz: Mechanical Engineering
Exam: UPPSC AE
Topic: Miscellaneous

Each question carries 1 mark
Negative marking: 1/4 mark
Time: 10 Minutes
Q1. Which of the following statements regarding thin and thick cylinders, subjected to internal pressure only, is/are correct?
1. A cylinder is considered thin when the ratio of its inner diameter to the wall thickness is less than 15.
2. In thick cylinders, tangential stress has highest magnitude at the inner surface of the cylinder and gradually decreases towards the outer surface.
(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2
L1Difficulty 3
QTags Mechanical
QCereator Paper Maker 10
Q2. Which one of the following statements regarding screw dislocation is correct?
(a) It lies parallel to its Burgers vector.
(b) It moves in the direction parallel to its Burgers vector.
(c) It initially requires very less force to move
(d) It moves very fast as compared to edge dislocation
L1Difficulty 3
QTags Mechanical
QCereator Paper Maker 10
Q3. In the study of phase diagrams, the rule which helps to calculate the relative proportions of liquid and solid material present in the mixture at any given temperature is known as
(a) Hume-Rothery rule
(b) Lever rule
(c) Gibb’s phase rule
(d) Empirical rule
L1Difficulty 3
QTags Mechanical
QCereator Paper Maker 10
Q4. The addition of alloying element nickel to cast iron will primarily improve
(a) Wear resistance
(b) Toughness
(c) Carbide formation
(d) Machinability
L1Difficulty 3
QTags Mechanical
QCereator Paper Maker 10
Q5. The maximum energy which can be stored in a body up to the elastic limit is called
(a) Proof resilience
(b) Modulus of resilience
(c) Impact toughness
(d) Endurance strength
L1Difficulty 3
QTags Mechanical
QCereator Paper Maker 10
Q6. In which one of the following tooth profiles, does the pressure angle remain constant throughout the engagement of teeth?
(a) Cycloidal
(b) Involute
(c) Conjugate
(d) Epicycloid
L1Difficulty 3
QTags Mechanical
QCereator Paper Maker 10
Q7. If the axes of the first and last wheels of a compound gear coincide, it is called
(a) Simple gear train
(b) Compound gear train
(c) Epicyclic gear train
(d) Reverted gear train
L1Difficulty 3
QTags Mechanical
QCereator Paper Maker 10
Q8. Coaxing is a process of_____.
(a) Improving the fatigue properties, attained by under-stressing and then raising the stress in small increments
(b) Decreasing the hardness by full annealing
(c) Increasing the uniaxial tensile strength by heating above recrystallization temperature and quenching in oil media
(d) Maintaining the ductility of the material by chemical treatment
L1Difficulty 3
QTags Mechanical
QCereator Paper Maker 10
Q9. For the prediction of ductile yielding, the theory of failure utilized is
(a) Maximum strain energy theory
(b) Distortion energy theory
(c) Maximum normal strain theory
(d) Mohr theory
L1Difficulty 3
QTags Mechanical
QCereator Paper Maker 10
Q10. Which of the following applications regarding Navier-Stokes equations are correct?
1. Laminar unidirectional flow between stationary parallel plates.
2. Laminar unidirectional flow between parallel plates having no relative motion.
3. Laminar flow in circuit pipes.
4. Laminar flow between concentric rotating cylinders.
(a) 1, 2 and 3 only
(b) 1, 3 and 4 only
(c) 1, 2 and 4 only
(d) 2, 3 and 4 only
L1Difficulty 3
QTags Mechanical
QCereator Paper Maker 10

SOLUTIONS
S1. Ans(d)
Sol.
S2. Ans(a)
Sol. In a screw dislocation, the dislocation lies in a direction parallel to Burger’s vector.
S3. Ans(b)
Sol. Lever rule is used to study the relative proportion of two phases present in an alloy, at any given temperature.
S4. Ans(b)
Sol. Nickel promotes formation of small discontinuous carbides and enhance toughness
S5. Ans(a)
Sol. The maximum energy which can be stored in a body upto elastic limit, is called proof resilience.
S6. Ans(b)
Sol. In involute profile tooth, because of the involute property to be satisfied, pressure angle does not change with point of contact position.
S7. Ans(d)
Sol. Reverted gear train is that compound gear train, which is used to connect co-axial shafts
S8. Ans(a)
Sol.
S9. Ans(b)
Sol. For ductile material MDET result is best.
S10. Ans(a)
Sol.

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