Engineering Metrology Questions and Answers Part-1

1. What is the angle between the two surfaces of an angle plate?
a) 45 degree
b) 120 degree
c) 90 degree
d) 180 degree

Answer: c
Explanation: Angle plate is an accessory used for measurement purpose along with surface plates and two surfaces of angle plate are at 90 degrees to each other.

2. Which of the following is correct about the hardness of angle plates?
a) Minimum hardness of 100 HB
b) Minimum hardness of 180 HB
c) Maximum hardness of 180 HB
d) Maximum hardness of 100 HB

Answer: b
Explanation: Angle plates are generally made of cast iron and have 180 HB minimum hardness. Angle plates are available in various designs.

3. What is the purpose of baffle plates?
a) Support angle plates
b) Protect casting from direct flame heat
c) Used as an accessory with surface plates
d) Support surface plates

Answer: b
Explanation: Baffle plate creates a barrier between flames and casting, and protects casting from direct heat generated by flames.

4. Which of the following is incorrect about angle plates?
a) Plates are given heat treatment after being finished
b) Angle plates can be used for inspection purposes
c) Box squares can be used instead of angle plates
d) Surfaces of angle plates are scraped

Answer: a
Explanation: Heat treatment is given to the angle plates before being finished to relieve internal stresses. Angle plates are widely used for inspection purposes. Surface of angle plates are scraped to give them a smooth finish and flatness.

5. How many faces are there in multipurpose angle plate?
a) About 50 faces
b) About 40 faces
c) About 30 faces
d) About 10 faces

Answer: d
Explanation: A multipurpose angle plate generally has 10 faces. All faces are at 90 degrees to each other and also perfectly and accurately ground.

6. What is the accuracy of the working surfaces of multipurpose angle plates?
a) 0.002 mm in 25 mm length
b) 0.005 mm in 25 mm length
c) 0.005 mm in 50 mm length
d) 0.002 mm in 50 mm length

Answer: a
Explanation: Working surfaces and end surfaces of plates should be square within the accuracy of 0.002 mm in 25 mm length and 0.005 mm in 25 mm length respectively.

7. Which of the following is true for threaded hole position?
a) Threaded holes are provided only on the sides of angle plates for handling purpose
b) Threaded holes are provided only on the faces of angle plates so that it can be used as fixture
c) Angle plates have threaded holes on the sides and faces so that it can be used as fixture
d) No threaded holes are present in angle plates

Answer: c
Explanation: Sometimes angle plates are used as fixture and for this threaded holes are made on sides and faces of plates. Fixture is a work locating and holding a device

8.What is the accuracy of surface straightness in angle plates?
a) ±0.001 mm in 25 mm length
b) ±0.01 mm in 25 mm length
c) ±0.04 mm in 25 mm length
d) ±0.004 mm in 25 mm length

Answer: a
Explanation: High accuracy of straightness is needed as straight planes are the basis for measurement works. Angle plates have ±0.001 mm in 25 mm length surface straightness.

9. Which option is correct about these two following statements regarding outer faces of angle plates?
Statement 1: Casting strains are eliminated by natural ageing.
Statement 2: Outer faces of angle plates have recessed grooves.
a) Only statement 1 is true
b) Both statements are false
c) Only statement 2 is true
d) Both statements are true

Answer: d
Explanation: Strain produced in the casting process is eliminated by either natural ageing or artificial seasoning. In natural ageing metal is kept at room temperature to gain its full strength. Outer faces of these plates have grooves for holding and locating purposes

10. Which of the following option is correct about given statements?
S1: Clamping pallets allows easy fixing of workpieces.
S2: In annealing furnace, angle plates are heating up to 10 degree Celsius.
S3: Straight edges can be used for checking the straightness of the parts.
a) T, T, F
b) F, T, F
c) F, F, T
d) T, F, T

Answer: d
Explanation: In heat treatment operation, angle plates are placed in annealing furnaces where it is heated up to 55oC (approx.). It should be maintained at this temperature for about 3 hours or more which depends upon the mass of casting.