Mechanical Engineering Past Papers MCQs

By: Prof. Dr. Fazal Rehman | Last updated: May 21, 2025

1. : Select the belt length when the diameter of the two pulleys are 550mm and 300mm if the centre distance is 2800mm.
(A) 6.5m
(B) 6.94m
(C) 4.66m
(D) 5.26m

2. : Band brake has a compound building with a large number of parts.
(A) Yes
(B) It has complicated construction but a small number of parts
(C) It has simple constructions but a large number of parts
(D) It has a simple construction

3. : Select the toughness of a material, when it is heated.
(A) decreases
(B) increases
(C) does not change
(D) both a and b

4. : Disk brakes mostly face the problem of self-locking.
(A) Yes
(B) Self-locking but it depends on the radius of the wheel rotating
(C) No
(D) Material dependent

5. : Disk brakes can be used for reverse rotation of the disk also.
(A) Poor efficiency in the opposite direction
(B) They can be used
(C) No they are effective for one direction of motion only
(D) None of the listed

6. : Select the number of slots in a 25 mm castle nut.
(A) 6
(B) 4
(C) 2
(D) 8

7. : At least one end of the band passes through the fulcrum, when we talk about both simple band brake and differential band brake.
(A) Both the ends
(B) One end
(C) Neither end
(D) All of the above

8. : When the maximum tension in the belt is 900N and the allowable belt load is 500N, compute the number of belts needed to transmit power.
(A) 4
(B) 3
(C) 2
(D) 5

9. : The belt tension is maximum if the velocity of the belt is 0.
(A) It has a constant value
(B) True
(C) It is velocity independent
(D) It maxes at v=infinity

10. : Can we prevent back rotation of the drum?
(A) Depends on the angular velocity
(B) No
(C) Yes by using back stop brake
(D) Only in some specific cases

11. : Select the braking torque if the tension in the two sides is 3500N and 1980N with a radius of drum being 160mm.
(A) None of the mentioned
(B) 278.6 N-m
(C) 223.4 N-m
(D) 243.20 N-m

12. : When the temperature grows coefficient of friction ________ in drum brakes,
(A) increases
(B) Can’t be determined
(C) remains the same
(D) decreases

13. : The term of loss of torque transmitting capacity at high temperatures is known as
(A) Drifting
(B) Rolling
(C) Fading
(D) Planking

14. : The Band brakes need which type of maintenance?
(A) Much
(B) Zero
(C) Little
(D) None of the above

15. : Screws used for power transmission should have
(A) Low efficiency
(B) High efficiency
(C) Very fine threads
(D) Strong teeth

16. : The disk brake torque is linearly proportional to the operating force.
(A) Independent of force
(B) No, it is proportional to its square
(C) Proportional to its cube
(D) Yes

17. : The sleeve or muff coupling is formed as
(A) Hollow shaft
(B) Thick cylinder
(C) Solid shaft
(D) Dun cylinder

18. : When the tensions in the belt are P₁ and P₂, then find P₁ – mv² / P₂ – mv². The contact angle for smaller pulley is 156°, groove angle is 36°, and coefficient of friction is 0.2.
(A) 6.21
(B) 4.66
(C) 5.83
(D) 5.36

19. : Compute the angle of the wrap when the diameter of the two pulleys are 550mm and 300mm, and centre distance is 2800mm.
(A) 159.3°
(B) 167.8°
(C) 174.8°
(D) None of the mentioned

20. : Compute the arc of contact when the diameter of the two pulleys are 550mm and 300mm, and centre distance is 2800mm.
(A) 1.02
(B) 1.03
(C) 1.01
(D) 1.04