This set of Engineering Metrology Multiple Choice Questions & Answers (MCQs) focuses on “V-Block”.
1. What is the use of V-Blocks?
a) For checking only squareness of square work pieces
b) For checking roundness
c) Only for the support purposes
d) To support triangular surfaces only
Explanation: V-Blocks are generally used for cylindrical workpieces to check their roundness and for marking centres. V-blocks are like precision metalworking jigs which are used to hold workpieces. These are available in market with wide range of varieties.
2. What is the bearing area of V-Blocks?
Explanation: Vee-Blocks have bearing area of greater than or equal to 20%. V-blocks are used for inspection and workshop purposes. A small groove is present at the bottom of the ‘V’. They are used with screw clamps for holding the work.
3. What is the symmetrisation accuracy of vees in V-Blocks?
a) 0.002 mm per 20 mm length
b) 0.001 mm per 20 mm length
c) No effect of symmetry
d) 0.02 mm per 20 mm length
Explanation: V blocks have symmetrisation accuracy of 0.002 mm per 20 mm length in Vs and straightness accuracy is ±0.01 mm per 20 mm length.
4. Which of the following is incorrect about V-Blocks?
a) V-Blocks should be checked periodically for accuracy
b) V-Blocks are used to establish centre axis of a cylindrical piece precisely
c) First check the V-Blocks visually before using
d) V-Blocks cannot be used with clamps
Explanation: V-blocks should be checked periodically for accuracy and also checked for scratches and dents. Sometimes clamps are used with V-Blocks to secure the work.
5. Which V block is used for checking triangle effect?
a) V block with 120-degree angle is used
b) V block with 90-degree angle is used
c) V block with 60-degree angle is used
d) V block with 30-degree angle is used
Explanation: V-blocks with 120 degree vee angle are available for some special purposes like checking triangle effect or taps. V-blocks with 90 degree angle are general purpose V-Blocks.
6. Which of the following grades is specified by IS : 2494-1964?
a) Two grades of vee Blocks, viz. Grade A and B
b) Four grades of vee Blocks, viz. Grade A, B, C and D
c) Two grades of vee Blocks, viz. Grade 1 and 2
d) Four grades of vee Blocks, viz. Grade 1, 2, 3 and 4
Explanation: Depending upon the accuracy there are two grades (grade A and grade B) are specified by IS : 2494-1964. Vee blocks should check periodically to correct inaccuracies in blocks if any.
7. Which of the following option is correct for the given statements about working surface of V blocks?
Statement 1: V-Blocks have only one working surface i.e. flanks of vees.
Statement 2: Side faces of V-blocks are not working surfaces.
a) Both statements are true
b) Statement 1 is correct
c) Statement 2 is correct
d) Both statements are false
Explanation: V-blocks generally have four working faces. These working faces are flanks of vees, base end faces, top and sides faces of V-blocks. They are generally supplied as matched pairs in which 2 V-blocks are of almost same size with same grade of accuracy.
8. Which of the following option is correct for the given statements related to V-blocks? (T=True/ F=False)
Statement 1: V-blocks can be used as a magnetic work holding device.
Statement 2: V-blocks with internal magnets help in milling operation.
a) T, T
b) T, F
c) F, T
d) F, F
Explanation: Some V-blocks also has internal magnet which can be used for holding magnetic work. V-blocks are widely used work holding device which can be used for many operations like drilling, grinding and milling.
9. Which of the following is correct for departure from flatness in Vees?
a) Any departure from flatness in vees should be a concavity
b) Any departure from flatness parallel to the vee axis should be a concavity
c) Any departure from flatness parallel to the vee axis should be a convexity
d) Any departure from flatness in vees can be a concavity or convexity
Explanation: Any departure from flatness on surfaces other than vees should be a concavity and from vees should be convexity. Any departure from flatness parallel to the vee axis should be a concavity.
10. Which of the following is incorrect about V blocks?
a) Cylindrical piece should be placed on the vee sides
b) Cylindrical piece should be placed on the edges of the vees
c) V-Blocks generally sold in pairs
d) V-blocks can support square, round and rectangular pieces
Explanation: Cylindrical pieces should not be placed on the edges; it should be on the vee sides otherwise there is an inaccuracy in marking centres. V-blocks are mostly used to hold cylindrical work pieces but it can also support square and rectangular pieces.
Sanfoundry Global Education & Learning Series – Engineering Metrology.
To practice all areas of Engineering Metrology, here is complete set of 1000+ Multiple Choice Questions and Answers.