BPSC AE 2025: Assistant Engineer (Civil/Mechanical/Electrical) (Advt. 29, 30 and 31/2025), Paper IV General Engineering Science
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Bihar Public Service Commission
Advt. No 29/2025, 30/2025 & 31/2025
General Engineering Science, Paper-IV
Exam Date: 18-07-2025, 2nd Shift
Final Answer Key (Set-A)
Q. No. Answer Key Q. No. Answer Key
1 A 26 A
2 Deleted 27 Deleted
3 C 28 D
4 C 29 A
5 D 30 A
6 B 31 A
7 A 32 A
8 C 33 B
9 D 34 D
10 B 35 C
11 B 36 D
12 C 37 D
13 C 38 A
14 B 39 B
15 D 40 B
16 B 41 B
17 C 42 A
18 D 43 Deleted
19 B 44 B
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Q. No. Answer Key Q. No. Answer Key
20 A 45 B
21 B 46 B
22 C 47 D
23 A 48 C
24 C 49 B
25 B 50 C
(Set-B)
Q. No. Answer Key Q. No. Answer Key
1 A 26 D
2 D 27 B
3 C 28 D
4 Deleted 29 B
5 A 30 D
6 D 31 D
7 D 32 A
8 D 33 D
9 D 34 C
10 B 35 D
11 B 36 A
12 D 37 D
13 A 38 B
14 A 39 C
15 B 40 C
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Q. No. Answer Key Q. No. Answer Key
16 A 41 B
17 D 42 A
18 C 43 D
19 D 44 B
20 B 45 C
21 C 46 B
22 A 47 C
23 Deleted 48 C
24 D 49 C
25 C 50 Deleted
(Set-C)
Q. No. Answer Key Q. No. Answer Key
1 A 26 A
2 A 27 B
3 C 28 Deleted
4 D 29 D
5 D 30 B
6 C 31 D
7 B 32 B
8 C 33 A
9 C 34 A
10 D 35 C
11 A 36 B
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Q. No. Answer Key Q. No. Answer Key
12 C 37 B
13 A 38 C
14 C 39 D
15 A 40 A
16 Deleted 41 A
17 A 42 C
18 A 43 A
19 D 44 D
20 C 45 C
21 D 46 D
22 A 47 A
23 D 48 A
24 B 49 Deleted
25 B 50 D
(Set-D)
Q. No. Answer Key Q. No. Answer Key
1 D 26 B
2 D 27 D
3 B 28 D
4 C 29 C
5 D 30 C
6 Deleted 31 C
7 A 32 C
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Q. No. Answer Key Q. No. Answer Key
8 D 33 D
9 B 34 C
10 A 35 D
11 C 36 A
12 D 37 D
13 D 38 B
14 B 39 A
15 B 40 B
16 B 41 D
17 Deleted 42 A
18 C 43 D
19 D 44 A
20 B 45 A
21 D 46 A
22 A 47 D
23 B 48 B
24 A 49 B
25 Deleted 50 D
Reason as per Set-A
Q.No.-02- Deleted.
Reason :- None of the options are correct. Hence the question is deleted.
Polar moment of inertia, J = (D4 - d4)
For a hollow Shaft
Outer radius, R = D/2
Polar Modulus = J/R = (D4 - d4) / D/2 =
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Q.No.-09- No change.
Reason :- A time and progress chart for construction is commonly known as a Gantt Chart
or a bar chart and also it can be called as Modified milestone chart. Thus, all the
options are correct.
Q.No.-27- Deleted.
Reason :- The azimuth of a heavenly body is the angle between the observer's meridian and
the vertical circle passing through the body.
Ref:- Surveying, Vol-III, by B.C Penmia, A.K. Jain and A.K. Jain, Laxmi
Publications (P) Ltd., Edition 2003.
None of the options are correct. Hence, the question is deleted.
Q.No.-28- No Change
Reason :- A higher specific heat ratio (ɣ) in otto cycle leads to higher thermal efficiency for
a given compression ratio.
Ref:- 1. Engineering thermodynamics by P.K. Nag
2. Thermodynamics by Cengel.
Q.No.-30- No Change
Reason :- The assumptions of thermal boundary layers are steady and incompressive flow
etc.
Ref:- Boundary layer theory by Hermann Schlichting.
Q.No.-36- No Change
Reason :- Best method for utilisation of coal as fuel to cause least amount of air pollution is
coal gasification.
Ref:- Power Plant Engineering by P.K. Nag.
Q.No.-43- Deleted.
Reason :- The purpose of an autocollimator is primarily to measure small angular
differences. It is also used for checking surface flatness, straightness, parallelism
and squareness with high sensitively and precision.
Therefore, option A, B and D are correct, but option C is not correct.
Hence, the question is deleted.Page 1 of 11
Source: Bihar Public Service Commission. Question paper published by Bihar Public Service Commission.