Quiz: Mechanical Engineering 08 May 2020

Quiz: Mechanical Engineering
Exam: ISRO (TECHNICAL ASST.)
Topic: Miscellaneous

Each question carries 4 mark.
Negative marking: 1 mark
Time: 15 Minute

Q1. Young’s modulus (E), Bulk modulus (K) and Shear modulus (G) are related by
(a) E=(K+G)/6K
(b) E=9KG/(3K+G)
(c) E=(9K+G)/6K
(d) E=(K+6G)/6K

Q2. Open circuit test on the transformer is to measure its
(a) Copper loss
(b) Leakage reactance
(c) Equivalent impedance
(d) Core loss

Q3. Mond process is used for extraction of
(a) Copper
(b) Steel
(c) Nickel
(d) Aluminium

Q4. Number of minimum control points required to generate a quadratic B-spline curve
(a) 2
(b) 3
(c) 4
(d) 5

Q5. Which is a positive drive?
(a) Flat belt drive
(b) Round belt drive
(c) Crossed belt drive
(d) Timing belt

Q6. De-aerator in thermal power plants is used to
(a) Remove dissolved gases from feed water
(b) Reduce temperature of feed water
(c) Reduce pressure of feed water
(d) None of the above

Q7. When the state is being changed from gas to liquid state through the process of condensation, the temperature?
(a) increases
(b) decreases
(c) remains constant
(d) may increase or decrease

Q8. Air refrigeration system operates on
(a) Carnot cycle
(b) Rankine cycle
(c) Reversed Carnot cycle
(d) Bell Coleman cycle

Q9. Crystal structure of Aluminium is
(a) Face centered cubic
(b) Body centered cubic
(c) Simple cubic
(d) hexagonal closed packed

Q10. The angle turned through by a Cam while its follower is stationary is called
(a) Pressure angle
(b) Angle of lap
(c) Dwell angle
(d) Friction angle

Solutions

S1. Ans (b)
Sol. Relation between E, K and G is
E=9KG/(3K+G)

S2. Ans (d)
Sol. The purpose of the open-circuit test is to determine the no-load current and losses of the transformer because of which their no-load parameters are determined. The core loss of the transformer can be determined by this test.

S3. Ans (c)
Sol. Mond process is used for the extraction of Nickel. This process converts Nickel oxide in to purified Nickel. In the extraction of Nickel or Ni, there is a very important role of CO. The CO serves as a reducing agent.

S4. Ans (b)
Sol. B-splines are a more general type of curve than Bezier curves. In a B-spline each control point is associated with a basis function. If the order of B-spline is n then we require (n+1) control points to generate B-spline. So, for quadratic B-spline, we need 3 control points.

S5. Ans (d)
Sol. As slip occurs in other given options, so these all are negative drive except timing belt.

S6. Ans (a)
Sol. De-aerator is fixed with the feed water tank of the boiler in power plants. It is used to remove dissolved gases from the water, which otherwise, causes reduction in heat transfer in the boiler and oxidation in the tubes of the boiler.

S7. Ans (c)
Sol. Temperature and pressure both remain constant in all the phase changing processes. Such as condensation, boiling, freezing etc. In the condensation process, heat of vaporization is released and vapor is converted into liquid.

S8. Ans (d)
Sol. Bell-Coleman cycle is an air refrigeration cycle. It uses air as refrigerant and this cycle is majorly used in aircrafts due to low weight per ton of refrigeration.

S9. Ans (a)
Sol. In FCC crystal, there are one atom at each of the corner and one atom at each of the face of the unit cell. Aluminium possesses FCC structure. Other examples of FCC are Gold (Au), Silver (Ag) etc.

S10. Ans (c)
Sol. There are three types of angle through which Cam turned while its motion-
1. Angle of ascent – Angle turned through by cam when the follower is rising.
2. Angle of dwell – Angle turned through by cam when the follower is not moving.
3. Angle of descent – Angle turned through by cam when the follower is going down.

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