UPPSC Lec'21 ME: Daily Practices Quiz. 21-Oct-2021

Quiz: Mechanical Engineering
Exam: UPPSC Lecturer
Topic: Miscellaneous

Each question carries 1 mark
Negative marking: 1/4 mark
Time: 6 Minutes

Q1. Consider the statements for a CNC lathe machine
1. The X-axis controls the cross-slide motion of the cutting tool
2. The Z-axis controls the travel of the carriage towards or away from the headstock
3. The Y-axis controls the motion of the job
4. The X-Y-Z axes are used for rotational movement of the table
Which of the above statements are correct?
(a) 1 and 3
(b) 1 and 2
(c) 3 and 4
(d) 2 and 3

Q2. Which of the following is incorrect for NC machine tool?
(a) Instruction undergoes electronic processing and outcome is the pulsed command
(b) Control unit sends signals to drive unit of machine tool and to magnetic box
(c) Instruction for manufacturing the components is written in coded language and read by tape recorder
(d) All of the above

Q3. The intensity of pressure at a depth h is equal to
(a) specific weight × depth
(b) specific volume × depth
(c) density × depth
(d) force depth

Q4. In PERT and CPM network, the dummy activity
(a) consumes time
(b) consumes resources
(c) is used to preserve the logic
(d) is a real activity

Q5. Stirling cycle consists of
(a) Two constant volume & two isothermal processes
(b) Two isothermal and two isentropic processes
(c) Two constant volume and two isentropic processes
(d) One constant volume, one constant pressure and two isentropic processes

Q6. Perpetual motion machine of second kind (PMM-II) violates the
(a) Zeroth law of thermodynamics
(b) First law of thermodynamics
(c) Second law of thermodynamics
(d) Third law of thermodynamics

Solution

S1. Ans. (b)
Sol. For lathes machine, the X-axis controls the motion of the cross-slide at a right angle to the spindle axis.
Generally, CNC lathes are two-axis machines i.e., X-axis and Z-axis and have no Y-axis.
The axis of motion that is parallel to the spindle axis is always the Z-axis. The Z-axis controls the travel of the carriage towards or away from the headstock

S2. Ans. (d)
Sol. All of the above statements are correct.

S3. Ans.(a)
Sol. P = (ρg) h
P = specific weight × height

S4. Ans.(c)
Sol. In PERT and CPM network the dummy activity is used to preserve the logic

S5. Ans. (b)
Sol. Stirling cycle consists of two constant volume and two isothermal processes.

S6. Ans. (c)
Sol. Perpetual motion machine of second kind (PMM-II) violates the second law of thermodynamics.