UPPSC Lec'21 ME: Daily Practices Quiz. 14-Oct-2021

Quiz: Mechanical Engineering
Exam: UPPSC Lecturer
Topic: Miscellaneous
Each question carries 1 mark
Negative marking: 1/4 mark
Time: 6 Minutes
Q1. Match List – (Metal forming process) with List – II (Associated force) and select the correct answer using the codes given below the lists:
List – I List – II
A. Wire drawing 1. Shear force
B. Extrusion 2. Tensile force
C. Blanking 3. Compressive force
D. Bending 4. Spring back force
Codes:
A B C D
(a) 4 2 1 3
(b) 2 1 3 4
(c) 2 3 1 4
(d) 4 3 2 1

Q2. The advantage of forging is?
(a) Good surface finish
(b) Low tooling cost
(c) Close tolerance
(d) Improved physical property

Q3. A cup of 10 cm height and 5 cm diameter is to be made from a sheet metal of 2 mm thickness. The number of deductions necessary will be
(a) one
(b) two
(c) three
(d) four

Q4. The bending force required for U-bending, V – bending and Edge – bending will be in the ratio of
(a) 1: 2: 0.5
(b) 2: 1: 0.5
(c) 1: 2: 1
(d) 1: 1: 1

Q5. Which one of the following lubricants is most suitable for drawing mild steel wires?
(a) Sodium stearate
(b) Water
(c) Lime – water
(d) kerosene

Q6. In rolling operating the maximum draft is given by (R = Radius of roll, μ = coefficient of friction
(a) μR
(b) μ √R
(c) μ^2 R^2
(d) μ^2 R

Solutions

S1. Ans.(c)
Sol. In wire drawing process, tensile force is acting to increase length and decrease diameter of the wire
In blanking and piercing operation, the operation is done by shearing action.
In Extrusion process, jobs are produced with the help of compressive force.
In bending of sheets, Spring back force is present.

S3. Ans.(d)
Sol. The advantage of forging is that the job has improved physical property.

S5. Ans.(c)
Sol. D=√(d^2+4dh)=√(5^2+4×5×10)=15
Limiting draw ratio=D/d=15/5=3
The number of deductions necessary will be three.

S7. Ans. (b)
Sol. The bending force required for U-bending, V – bending and Edge – bending will be in the order of
U – bending > V – bending > Edge – bending

S19. Ans.(c)
Sol. Lime – water is most suitable as lubricants for drawing mild steel wires.

S27. Ans.(d)
Sol. In rolling operation,
∆h_max = μ²R