Question Details

A shaft of diameter  25 0.07 0.04 mm is assembled in a hole of diameter  25 0.00 + 0.02 mm. Match the allowance and limit parameter in Column I with its corresponding quantitative value in Column II for this shaft-hole assembly.

Allowance and limit parameter
(Column I)
Quantitative value
(Column II)
P.
Allowance
1.0.09 mm
Q.
Maximum clearance
2.24.96 mm
R.Maximum material limit for hole
3.0.04 mm

4.25.0 mm

Options

A

P-3, Q-1, R-4

B

P-3, Q-1, R-4

C

P-3, Q-1, R-4

D

P-3, Q-1, R-2

Correct Answer :

P-3, Q-1, R-4

Solution :

The correct option is P-3, Q-1, R-4.

Analysis of the Given Data:
Based on the problem statement and the accompanying diagram, we have a shaft-hole assembly with a basic size of 25 mm. The diagram explicitly details the tolerance zones relative to the "Reference Line" representing the basic size of 25 mm, indicating the shaft tolerance zone (labeled "Shaft" with deviations of 0.04 mm and 0.07 mm below the basic size line) and the hole tolerance zone (with a deviation of 0.02 mm above the reference line).
Let us calculate the limits of sizes for both the shaft and the hole:

1. Shaft Limits:
Basic size of the shaft = 25 mm
Upper limit of the shaft (maximum shaft diameter):
d max = 25 0.04 = 24.96  mm
Lower limit of the shaft (minimum shaft diameter):
d min = 25 0.07 = 24.93  mm

2. Hole Limits:
Basic size of the hole = 25 mm
Upper limit of the hole (maximum hole diameter):
D max = 25 + 0.02 = 25.02  mm
Lower limit of the hole (minimum hole diameter):
D min = 25 0.00 = 25.00  mm

Step-by-Step Match:

P. Allowance:
Allowance is defined as the intentional difference between the maximum material limits of mating parts. For a clearance fit, it is the minimum clearance:
Allowance = Minimum Clearance = D min d max
Substituting the values:
Allowance = 25.00 24.96 = 0.04  mm
Thus, P matches with 3.

Q. Maximum clearance:
Maximum clearance occurs when the hole is at its maximum limit and the shaft is at its minimum limit:
Maximum Clearance = D max d min
Substituting the values:
Maximum Clearance = 25.02 24.93 = 0.09  mm
This is also visual in the diagram notes where it calculates maximum clearance as (0.07 + 0.02) = 0.09 mm.
Thus, Q matches with 1.

R. Maximum material limit for hole:
The Maximum Material Condition (MMC) for a hole corresponds to the condition where it contains the maximum amount of material (i.e., when the hole is at its smallest allowable size). Therefore:
Maximum Material Limit for Hole = D min = 25.00  mm
Thus, R matches with 4.

Conclusion:
Combining the matches, we get: P-3, Q-1, R-4.

Unlock Our Free Library

Access expert-curated educational resources and study materials—completely free.