MCQOPTIONS
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MCQOPTIONS
This section includes 53 Mcqs, each offering curated multiple-choice questions to sharpen your Machine Design knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Active and inactive, both types of coils support the load although both don’t participate in spring action. |
| A. | Active coils don’t support the load |
| B. | Inactive coils don’t support the load |
| C. | Both active and inactive don’t support the load |
| D. | Both active and inactive support the load |
| Answer» C. Both active and inactive don’t support the load | |
| 2. |
The helix angle is very small about 2⁰. The spring is open coiled spring. |
| A. | Yes |
| B. | It is closed coiled spring |
| C. | That small angle isn’t possible |
| D. | None of the listed |
| Answer» C. That small angle isn’t possible | |
| 3. |
A closely-coiled helical spring is made of 10 mm diameter steel wire, with the coil consisting of 10 turns with a mean diameter 120 mm. The spring carries an axial pull of 200 N. What is the value of shear stress-induced in the spring neglecting the effect of stress concentration and of deflection in the spring, when the modulus of rigidity is 80 kN/mm2? |
| A. | 63.5 N/mm2 and 34.6 mm |
| B. | 54.2 N/mm2 and 34.6 mm |
| C. | 63.5 N/mm2 and 42.6 mm |
| D. | 4.2 N/m2 and 42.6 mm |
| Answer» B. 54.2 N/mm2 and 34.6 mm | |
| 4. |
A machine mounted on a single coil spring has a period of free vibration of T. If the spring is cut into four equal parts and placed in parallel and the machine is mounted of them, then the period of free vibration of the new system will be: |
| A. | 16T |
| B. | T/4 |
| C. | 4T |
| D. | T/16 |
| Answer» C. 4T | |
| 5. |
A helical spring has N turns of coil diameter D and a second spring, made of same wire diameter and same material, has N/2 turns of coil of diameter 2D. If the stiffness of the first spring is k, then the stiffness of the second spring will be |
| A. | k/4 |
| B. | k/2 |
| C. | 2k |
| D. | 4k |
| Answer» B. k/2 | |
| 6. |
A mass is suspended at the bottom of two springs in series having stiffness 10 N/mm and 5 N/mm. The equivalent spring stiffness of the two Springs is nearly |
| A. | 0.3 N/mm |
| B. | 3.3 N/mm |
| C. | 5 N/mm |
| D. | 15 N/mm |
| Answer» C. 5 N/mm | |
| 7. |
A spring is made of a wire of 2 mm diameter having a shear modulus of 80 GPa. The mean coil diameter is 20 mm and the number of active coils is 10. If the mean coil diameter is reduced to 10 mm, the stiffness of the spring is: |
| A. | Increased by 16 times |
| B. | Decreased by 8 times |
| C. | Increased by 8 times |
| D. | Decreased by 16 times |
| Answer» D. Decreased by 16 times | |
| 8. |
A helical compression spring of stiffness K is cut into two pieces, each having equal number of turns and kept side by side under compression. The equivalent spring stiffness of this new arrangement is equal to: |
| A. | 4K |
| B. | 2K |
| C. | K |
| D. | 0.5K |
| Answer» B. 2K | |
| 9. |
If two closely coiled helical springs A & B with the mean diameter of spring A is half of that of spring B and having an equal number of active coils and same wire diameter are subjected to a same axial load of W, then the ratio of deflection in spring A to B. |
| A. | \(\frac{1}{8}\) |
| B. | \(\frac{1}{4}\) |
| C. | 2 |
| D. | 8 |
| Answer» B. \(\frac{1}{4}\) | |
| 10. |
A close helical spring of 100 mm mean diameter is made of 10 mm diameter rod, and has 20 turns. The spring carries an axial load of 200 kN with G = 8.4 × 104 N/mm2. The stiffness of the spring is nearly |
| A. | 5.25 N/mm |
| B. | 6.50 N/mm |
| C. | 7.25 N/mm |
| D. | 8.50 N/mm |
| Answer» B. 6.50 N/mm | |
| 11. |
A single-story building model is shown in the figure. The rigid bar of mass 'm' is supported by three massless elastic columns whose ends are fixed against rotation. For each of the columns, the applied lateral force (P) and corresponding moment (M) is also shown in the figure. The lateral deflection (δ) of the bar is given by \(\delta = \dfrac{PL^3}{12 EI}\), where L is the effective length of the column, E is Young's modulus of elasticity and I is the area moment of inertia of the column cross-section with respect to its neutral axis. For the lateral deflection profile of the columns, as shown in the figure, the natural frequency of the system for horizontal oscillation is |
| A. | \(\dfrac{1}{L}\sqrt{\dfrac{2EI}{m}} \ \rm rad/s\) |
| B. | \(2\sqrt{\dfrac{6EI}{mL^3}} \ \rm rad/s\) |
| C. | \(6\sqrt{\dfrac{EI}{mL^3}} \ \rm rad/s\) |
| D. | \(\dfrac{2}{L}\sqrt{\dfrac{EI}{m}} \ \rm rad/s\) |
| Answer» D. \(\dfrac{2}{L}\sqrt{\dfrac{EI}{m}} \ \rm rad/s\) | |
| 12. |
Normally spring operates within |
| A. | Elastic limits |
| B. | Plastic limits |
| C. | Elastic-Plastic limits |
| D. | All of the above |
| Answer» B. Plastic limits | |
| 13. |
A closely coiled helical spring of 20 cm mean diameter is having 25 coils of 2 cm diameter rod. The modulus of rigidity of the material is 107 N/cm2. What is the stiffness for the spring in N/cm? |
| A. | 50 |
| B. | 100 |
| C. | 250 |
| D. | 500 |
| Answer» C. 250 | |
| 14. |
In helical compression spring design formula:\(K\left ( \frac{8PC}{\pi d^2}\right)\)where P = load, C = spring index, d = wire diameter, and K = Wahl's factorThe Wahl factor takes into account: |
| A. | the bending stress due to helix of the spring |
| B. | the direct shear and the curvature of the spring |
| C. | the elastic constants (modulus of rigidity and Poisson's ratio) of the spring |
| D. | the effect of the inactive number of coils at the ends of the spring |
| Answer» C. the elastic constants (modulus of rigidity and Poisson's ratio) of the spring | |
| 15. |
In a helical coil spring, if C is the spring index, then the shear stress correction factor is given by: |
| A. | \({K_s} = \frac{1}{{2C}}\) |
| B. | \({K_s}=\frac{2C}{{2C+1}}\) |
| C. | \({K_s}=\frac{2C+1}{{2C}}\) |
| D. | \({K_s}=\frac{C+1}{{2C}}\) |
| Answer» D. \({K_s}=\frac{C+1}{{2C}}\) | |
| 16. |
If two springs k1 and k2 are placed in parallel, the combined stiffness of spring is |
| A. | k1 + k2 |
| B. | k1 + k2 / (k1 k2) |
| C. | (k1 k2) / k1 + k2 |
| D. | k1 k2 |
| Answer» B. k1 + k2 / (k1 k2) | |
| 17. |
A closed coiled helical spring is subjected to axial load (W) and absorbs 100 Nm energy at 4 cm compression. The value of axial load will be: |
| A. | 2.5 kN |
| B. | 5.0 kN |
| C. | 10.0 kN |
| D. | 12.5 kN |
| Answer» C. 10.0 kN | |
| 18. |
A coil-spring of stiffness k is cut exactly at the middle and the two springs thus made are arranged in parallel to take up together a compressive load. The equivalent stiffness of the two springs is |
| A. | 0.25k |
| B. | 0.5k |
| C. | 2k |
| D. | 4k |
| Answer» E. | |
| 19. |
A uniform T-shaped arm of weight W, pinned about a horizontal point C, is supported by a vertical spring of stiffness K. The extension of the spring is |
| A. | \(\frac{{3\;W}}{{4\;K}}\) |
| B. | \(\frac{{4\;W}}{{3\;K}}\) |
| C. | \(\frac{{3\;K}}{{4\;W}}\) |
| D. | \(\frac{{4\;K}}{{3\;W}}\) |
| Answer» C. \(\frac{{3\;K}}{{4\;W}}\) | |
| 20. |
A helical spring of 10 N/mm rating is mounted on top of another helical spring of 8 N/mm rating. The force required for a total combined deflection of 45 mm through the two springs is |
| A. | 100 N |
| B. | 150 N |
| C. | 200 N |
| D. | 250 N |
| Answer» D. 250 N | |
| 21. |
Laminated springs are generally- |
| A. | Loaded at ends and supported at the centre |
| B. | Loaded at the centre and supported at ends |
| C. | Loaded as well as supported at the centre |
| D. | Loaded as well as supported at ends |
| Answer» C. Loaded as well as supported at the centre | |
| 22. |
A compression spring is made of a music wire of 2 mm diameter having a shear strength and shear modulus of 800 MPa and 80 GPa respectively. The mean coil diameter is 20 mm, the free length is 40 mm and the number of active coils is 10. If the mean coil diameter is reduced to 10 mm, the stiffness of the spring is approximately |
| A. | Decreased by 8 times |
| B. | Decreased by 2 times |
| C. | Increased by 2 times |
| D. | Increased by 8 times |
| Answer» E. | |
| 23. |
A close-coiled helical spring of 10 active turns is made of 8 mm diameter steel wire. The mean coil diameter is 10 cm. If G = 80 GPa for the material of spring, the extension of spring under a tensile load of 200 N will be nearly |
| A. | 40 mm |
| B. | 45 mm |
| C. | 49 mm |
| D. | 53 mm |
| Answer» D. 53 mm | |
| 24. |
For the structure shown in the figure, all of I, EI and L are of respective unit values. The equivalent stiffness constant for the structure is |
| A. | 1 |
| B. | 1.5 |
| C. | 4.5 |
| D. | 9 |
| Answer» D. 9 | |
| 25. |
For the spring system given in the figure, the equivalent stiffness is |
| A. | 0.4 k |
| B. | 4 k |
| C. | 2.5 k |
| D. | k |
| Answer» B. 4 k | |
| 26. |
In a close-coiled helical spring |
| A. | plane of the coil and axis of the spring are closely attached |
| B. | angle of helix is large |
| C. | Plane of the coil is normal to the axis of the spring |
| D. | Deflection is small |
| Answer» D. Deflection is small | |
| 27. |
A spring used to absorb shocks and vibrations is |
| A. | Torsion spring |
| B. | Conical spring |
| C. | Leaf spring |
| D. | Disc spring |
| Answer» D. Disc spring | |
| 28. |
A closed-coil helical spring is subjected to a torque about its axis. The spring wire would experience a |
| A. | Bending stress |
| B. | Direct tensile stress of uniform intensity at its cross-section |
| C. | Direct shear stress |
| D. | Torsional shearing stress |
| Answer» B. Direct tensile stress of uniform intensity at its cross-section | |
| 29. |
A helical coil spring with wire diameter d and mean coil diameter D is subjected to axial load. A constant ratio of D and d has to be maintained, such that the extension of the spring is independent of D and d. What is the ratio? |
| A. | \(\frac{{{D^3}}}{{{d^4}}}\) |
| B. | \(\frac{{{d^3}}}{{{D^4}}}\) |
| C. | \(\frac{{{D^{\frac{4}{3}}}}}{{{d^3}}}\) |
| D. | \(\frac{{{d^{\frac{4}{3}}}}}{{{D^3}}}\) |
| Answer» B. \(\frac{{{d^3}}}{{{D^4}}}\) | |
| 30. |
In a system, two connected rigid bars AC and BC are of identical length, L with pin supports at A and B. The bars are interconnected at C by a frictionless hinge. The rotation of the hinge is restrained by a rotational spring of stiffness, k. The system initially assumes a straight line configuration, ACB. Assuming both the bars as weightless, the rotation at supports, A and B, due to a transverse load, P applied at C is: |
| A. | \(\frac{{PL}}{{4k}}\) |
| B. | \(\frac{{PL}}{{2k}}\) |
| C. | \(\frac{P}{{4k}}\) |
| D. | \(\frac{{Pk}}{{4L}}\) |
| Answer» B. \(\frac{{PL}}{{2k}}\) | |
| 31. |
A closely-coiled helical spring of round steel wire 5 mm in diameter having 12 complete coils of 50 mm mean diameter is subjected to an axial load of 100 N. If modulus of rigidity is 80 GPa, the deflection of the spring will be |
| A. | 36 mm |
| B. | 32 mm |
| C. | 28 mm |
| D. | 24 mm |
| Answer» E. | |
| 32. |
A helical coil spring of stiffness k is cut to two equal halves and then these are connected in parallel to support a vibrating mass m. The angular frequency of vibration, ωn is |
| A. | \(\sqrt {\frac{k}{m}} \) |
| B. | \(\sqrt {\frac{2k}{m}} \) |
| C. | \(\sqrt {\frac{4k}{m}} \) |
| D. | \(\sqrt {\frac{k}{4m}} \) |
| Answer» D. \(\sqrt {\frac{k}{4m}} \) | |
| 33. |
A weight of 240 N is dropped on to a close-coiled helical spring made up of 18 mm spring steel wire. the spring consists of 22 coils wound to a diameter of 180 mm. If the instantaneous compression is 120 mm, what is the height of drop of the weight, given G = 88 × 103 N / mm2? |
| A. | 450 mm |
| B. | 300 mm |
| C. | 250 mm |
| D. | 150 mm |
| Answer» E. | |
| 34. |
A linear helical spring with spring constant k is cut into two equal halves. The spring constants of the individual halves will be |
| A. | k/2 |
| B. | k/√2 |
| C. | √2k |
| D. | 2k |
| Answer» E. | |
| 35. |
A closely coiled helical spring made of 10 mm diameter steel wire has 15 coils of 100 mm mean diameter. The spring is subjected to an axial load of 100 N. For a modulus of rigidity of 8.16 × 104 N/mm2, the stiffness of the spring will be nearly |
| A. | 5.9 N/mm |
| B. | 6.8 N/mm |
| C. | 7.7 N/mm |
| D. | 8.8 N/mm |
| Answer» C. 7.7 N/mm | |
| 36. |
In a closed helical spring subjected to an axial load, other quantities remaining the same, if the wire diameter is doubled and mean radius of the coil is also doubled, then stiffness of spring when compared to original one will become _____. |
| A. | Twice |
| B. | Four times |
| C. | Eight times |
| D. | Sixteen times |
| Answer» B. Four times | |
| 37. |
A helical spring has coil diameter 50 mm and is subject to axial load W. Another spring has coil diameter 25 mm, but otherwise identical to the first. The deflection of second spring will be ________ of that of first spring. |
| A. | \(\frac{1}{2}\) |
| B. | \(\frac{1}{4}\) |
| C. | \(\frac{1}{8}\) |
| D. | None of these |
| Answer» D. None of these | |
| 38. |
A helical spring has spring constant k. If the wire diameter, spring diameter and the number of coils is all doubled then the spring constant of the new spring becomes |
| A. | k/2 |
| B. | k |
| C. | 8k |
| D. | 16k |
| Answer» C. 8k | |
| 39. |
A spring of stiffness 50 N/mm is mounted on top of second spring of stiffness 100 N/mm. What will be the deflection under the action of 500 N? |
| A. | 3.33 mm |
| B. | 5 mm |
| C. | 10 mm |
| D. | 15 mm |
| Answer» E. | |
| 40. |
IF_THE_SPRING_IS_COMPRESSED_COMPLETELY_AND_THE_ADJACENT_COILS_TOUCH_EACH_OTHER,THE_THE_LENGTH_OF_SPRING_IS_CALLED_AS??$ |
| A. | Solid length |
| B. | Compressed length |
| C. | Free length |
| D. | None of the mentioned |
| Answer» B. Compressed length | |
| 41. |
Compressed length is smaller than the solid length.$ |
| A. | True |
| B. | False |
| Answer» C. | |
| 42. |
If_number_of_coils_are_8_and_wire_diameter_of_spring_3mm,_then_solid_length_is_given_by?$ |
| A. | None of the listed |
| B. | 27mm |
| C. | 24mm |
| D. | 21mm |
| Answer» D. 21mm | |
| 43. |
Active and inactive, both types of coils support the load although both don’t participate in spring action.$ |
| A. | Active coils don’t support the load |
| B. | Inactive coils don’t support the load |
| C. | Both active and inactive don’t support the load |
| D. | Both active and inactive support the load |
| Answer» C. Both active and inactive don‚Äö√Ñ√∂‚àö√ë‚àö¬•t support the load | |
| 44. |
If uncompressed length of spring is 40mm and number of coils 10mm, then pitch of coil is? |
| A. | 4 |
| B. | 40/9 |
| C. | 40/11 |
| D. | None of the mentioned |
| Answer» C. 40/11 | |
| 45. |
Pitch_of_coil_is_defined_as_axial_distance_in_compressed_state_of_the_coil. |
| A. | Yes |
| B. | It is measured in uncompressed state |
| C. | It is same in uncompressed or compressed state |
| D. | None of the listed |
| Answer» C. It is same in uncompressed or compressed state | |
| 46. |
A spring with index=15 is prone to buckling? |
| A. | True |
| B. | False |
| Answer» B. False | |
| 47. |
If spring index=2.5, what can be concluded about stresses in the wire? |
| A. | They are high |
| B. | They are negligible |
| C. | They are moderate |
| D. | Cannot be determined |
| Answer» B. They are negligible | |
| 48. |
The spring index is the ratio of wire diameter to mean coil diameter. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 49. |
Multi leaf springs are not recommended for automobile and rail road suspensions. |
| A. | True |
| B. | False |
| Answer» C. | |
| 50. |
The longest leaf in a leaf spring is called centre leaf. |
| A. | It is called middle leaf |
| B. | It is called master leaf |
| C. | Yes |
| D. | None of the listed |
| Answer» C. Yes | |