Engineering Metrology Multiple Choice Questions on “Terminology”.
1. What does ‘50’ represents in 50H8/g7?
a) Basic size
b) Actual size
c) Maximum limit of size
d) Minimum limit of size
Answer: a
Clarification: 50 represent the basic size of the hole and shaft. H and g are the positions of tolerance zone with respect to zero line for hole and shaft respectively. 8 and 7 are the tolerance size.
2. What is ‘Go limit’?
a) Lower limit of shaft and upper limit of hole
b) Lower limit of shaft and hole
c) Upper limit of shaft and lower limit of a hole
d) Upper limit of shaft and hole
Answer: c
Clarification: ‘Go limit’ deals with upper limit of shaft and lower limit of hole and refers to the maximum material condition. ‘No-go’ limits deals with lower limit of shaft and upper limit of hole and refers to the minimum material condition.
3. Which of the following is incorrect regarding terminology?
a) Grades of tolerances decides manufacture’s accuracy
b) For any basic size there are 20 different shafts
c) Line of zero deviation is known as zero line
d) Tolerance has no sign
Answer: b
Clarification: For any basic size, there are 25 different shafts. These are designated by small letters from a to zc. Each shaft has 20 tolerance grades. Tolerance is the algebraic difference between lower and upper deviation.
4. What is the actual deviation?
a) Algebraic sum between actual size and corresponding basic size
b) Algebraic difference between actual and corresponding basic size
c) Average of actual and basic size
d) Algebraic difference between upper and lower deviation
Answer: b
Clarification: Algebraic difference between a size and a corresponding basic size is called deviation. Limit deviations are upper and lower deviations. Algebraic difference of actual size with basic size is called actual deviation.
5. What is the condition for a positive upper deviation?
a) Maximum limit of size > basic size
b) Maximum limit of size is < basic size
c) Minimum limit of size > basic size
d) Maximum limit of size < basic size
Answer: a
Clarification: Upper deviation is positive when maximum limit of size > its basic size and negative when maximum limits size < basic size. For lowers deviations, it is a positive quantity when minimum limit size is more than its corresponding basic size.
6. How many holes are there for any basic size?
a) 22
b) 24
c) 26
d) 28
Answer: d
Clarification: There are 28 different holes for any basic size. These are designated by capital letters. A, B, CD, C, D, E, EF, F, FG, G, H, JS, J, K, M, N, P, R, S, T, U, V, X, Y, Z, ZA, ZB, ZC these are the 28 holes.
7. What does ES represent in terminology as per IS: 919?
a) Lower deviation of hole
b) Upper deviation of shaft
c) Lower deviation of shaft
d) Upper deviation of hole
Answer: d
Clarification: ‘ES’ and ‘es’ represents upper deviation for hole and shaft respectively. ‘EI’ and ‘ei’ represents lower deviation for hole and shaft respectively.
8. What is ‘IT01’?
a) Basic size of hole
b) Basic size of shaft
c) Tolerance grade
d) Standard tolerance factor