MCQOPTIONS
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MCQOPTIONS
This section includes 50 Mcqs, each offering curated multiple-choice questions to sharpen your NTPC (Technical Ability) knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
If Break-even point = Total fixed cost \[\left( 1-\frac{Variable\text{ }cost\text{ }per\text{ }unit}{X} \right),\]Then X is the: |
| A. | Overheads |
| B. | price per unit |
| C. | 660 N-m |
| D. | materials cost |
| Answer» C. 660 N-m | |
| 2. |
A short column of external diameter D and internal diameter d carries an eccentric load d. The greatest eccentricity which the load can have without producing tension on the cross-section of the column would be |
| A. | \[\frac{d+D}{8}\] |
| B. | \[\frac{{{d}^{2}}+{{D}^{2}}}{8d}\] |
| C. | A\[\to \]3, B\[\to \]1, C\[\to \]4, D\[\to \]3 |
| D. | \[\sqrt{\frac{{{d}^{2}}+{{D}^{2}}}{8}}\] |
| Answer» C. A\[\to \]3, B\[\to \]1, C\[\to \]4, D\[\to \]3 | |
| 3. |
A solid circular shaft is subjected to pure torsion. The ratio of maximum shear stress to maximum normal stress at any point would be |
| A. | 1 : 1 |
| B. | 0.0430555555555556 |
| C. | 1 and 4 |
| D. | 0.0854166666666667 |
| Answer» B. 0.0430555555555556 | |
| 4. |
The state of plane stress in a plate of 100 mm thickness is given as \[{{\sigma }_{x\,x}}=100\,\,\text{N/m}{{\text{m}}^{\text{2}}},\] \[{{\sigma }_{x\,y}}=200\,\,\text{N/m}{{\text{m}}^{\text{2}}},\] Young's modulus \[=300\,\,\text{N/m}{{\text{m}}^{\text{2}}}\] Poission?s ratio = 0.3 The stress developed in the direction of thickness is |
| A. | Zero |
| B. | \[90\,\,\text{N/m}{{\text{m}}^{\text{2}}}\] |
| C. | Prevent cold cracks |
| D. | \[200\,\,\text{N/m}{{\text{m}}^{\text{2}}}\] |
| Answer» C. Prevent cold cracks | |
| 5. |
The degree of reaction of a turbine is defined as the ratio of: |
| A. | Static pressure drop to total energy transfer |
| B. | Total energy transfer to static pressure drop. |
| C. | A\[\to \]2, B\[\to \]3, C\[\to \]5, D\[\to \]1 |
| D. | Velocity energy to pressure energy. |
| Answer» B. Total energy transfer to static pressure drop. | |
| 6. |
Circumferential stress in a cylindrical steel boiler shell under internal pressure is 80 MPa, Young's modulus of elasticity and Poisson's ratio are respectively \[2\,\,\times \,\,{{10}^{5}}\] MPa and 0.28. The magnitude of circumferential strain in the boiler shell will be: |
| A. | \[3.44\times {{10}^{-\,4}}\] |
| B. | \[3.84\times {{10}^{-\,4}}\] |
| C. | 2, 1, 3 |
| D. | \[4.56\times {{10}^{-\,4}}\] |
| Answer» B. \[3.84\times {{10}^{-\,4}}\] | |
| 7. |
Consider the following 1. Safety valve. 2. Steam trap 3. Steam separator 4. Economiser. Among these the boiler accessories would" include: |
| A. | 1, 2 and 3 |
| B. | 2, 3 and 4 |
| C. | 2 and 3 only |
| D. | 1, 2, 3 and 4 |
| Answer» C. 2 and 3 only | |
| 8. |
Two hollow shafts of the same material have the same length and outside diameter. Shaft 1 has internal diameter equal to one-third of the outer diameter and shaft 2 has internal diameter equal to half of the outer diameter. If both the shafts are subject to the same torque, the ratio of their twists \[{{\theta }_{1}}/{{\theta }_{2}}\] will be equal to: |
| A. | 16/81 |
| B. | 8/27 |
| C. | 1, 3 and 4 |
| D. | 243/256 |
| Answer» E. | |
| 9. |
In a Parson's turbine stage, blade velocity is 320 m/s at the mean radius and the rotor blade exit angle is 30". For minimum kinetic energy of the steam leaving the stage, the steam velocity at the exit of the stator will be: |
| A. | \[640/\sqrt{3}\,\text{m/s}\] |
| B. | 640 m/s |
| C. | 1 and 3 |
| D. | \[160/\sqrt{3}\,\text{m/s}\] |
| Answer» D. \[160/\sqrt{3}\,\text{m/s}\] | |
| 10. |
For a free vortex design of blade in the rotor of a reaction axial turbine, the specific work along the blade height is: |
| A. | Higher at the blade hub and lower at the blade tip |
| B. | Constant from huh to tip |
| C. | Suitability for joint design |
| D. | Same at the hub and tip but different from the mean section. |
| Answer» B. Constant from huh to tip | |
| 11. |
A circular disc rolls without slip on an inclined plane. The ratio of its rotational kinetic energy to the total energy is: |
| A. | \[\frac{1}{4}\] |
| B. | \[\frac{1}{2}\] |
| C. | Brazing |
| D. | \[\frac{2}{3}\] |
| Answer» D. \[\frac{2}{3}\] | |
| 12. |
Which of the following statements are correct? (1) Impulse turbine rotor blades are thick at the Centre. (2) Rateau turbine is more efficient than Curtis turbine. (3) Blade velocity coefficient for an impulse turbine is of the order of 60%. Select the correct answer using the codes given below: |
| A. | 1, 2 and 3 |
| B. | 1 and 2 |
| C. | Argon arc welding |
| D. | 2 and 3 |
| Answer» C. Argon arc welding | |
| 13. |
The law of conservation of mechanical energy is valid: |
| A. | Irrespective of the mature of force held |
| B. | In gravitational field |
| C. | 3 and 4 |
| D. | Only if the force is tangential to the trajectory. |
| Answer» D. Only if the force is tangential to the trajectory. | |
| 14. |
The principle of conservation of energy cannot be applied in case of: |
| A. | A particle moving in gravitational field |
| B. | Flow of heat through a metal |
| C. | 2 and 3 |
| D. | Sliding of a particle along inclined plane with friction. |
| Answer» E. | |
| 15. |
A cage with a parrot sitting in it is suspended from a spring balance. The parrot starts flying. The reading of the spring balance will: |
| A. | Increase |
| B. | decrease |
| C. | Plasma arc welding |
| D. | be zero |
| Answer» C. Plasma arc welding | |
| 16. |
A man throws bricks to a height of 12 m where they reach with a speed of 12 m/s. If he throws the bricks such that they just reach that height. What percentage of energy will he save? |
| A. | 19% |
| B. | 0.26 |
| C. | Grey cast iron |
| D. | 0.57 |
| Answer» D. 0.57 | |
| 17. |
If the kinetic energy of the body becomes four times its initial value then the new: |
| A. | Three times its initial value |
| B. | Four times its initial value |
| C. | Edge welding |
| D. | Unchanged |
| Answer» D. Unchanged | |
| 18. |
A train of weight 5000 kN is pulled on a level track with a constant speed of 10 m/s. The frictional force is 75 kN. The power of the engine is: |
| A. | 375 kW |
| B. | 750 kW |
| C. | Laser beam welding employs a vacuum chamber and thus avoids use of a shielding method |
| D. | 3000 kW |
| Answer» C. Laser beam welding employs a vacuum chamber and thus avoids use of a shielding method | |
| 19. |
A mechanical system can be said to be conservative if the: |
| A. | Potential energy of the system remains constant |
| B. | Kinetic energy of the system remains constant |
| C. | Copper, cast iron, MS, aluminium |
| D. | Linear momentum remains constant |
| Answer» D. Linear momentum remains constant | |
| 20. |
A man is pulling a bucket of water up to the roof of a building of 6 m height. The total weight of the rope is 20 N and the weight of the bucket with water is 100 N. The work done by the man is: |
| A. | 720 N-m |
| B. | 420 N-m |
| C. | 2 alone |
| D. | 600 N-m |
| Answer» D. 600 N-m | |
| 21. |
When compared to stable flow, for supersaturated flow of steam through a nozzle the available enthalpy drop: |
| A. | Remains the same |
| B. | increases |
| C. | 4 |
| D. | is unpredictable. |
| Answer» D. is unpredictable. | |
| 22. |
A ball A of mass m falls under gravity from a height h and strikes another ball B of mass m which is supported at rest on a spring of stiffness k. Assume perfectly elastic impact. Immediately after the impact: |
| A. | The velocity of ball A is (1/2) \[\sqrt{2}\,\,gh\] |
| B. | The velocity of ball A is zero |
| C. | 300 |
| D. | None of the above. |
| Answer» C. 300 | |
| 23. |
A ball falls from a height of 1 m, hits the ground and rebounds with half its velocity just before impact Then after rising it falls and hits the ground and again rebounds with half its velocity just before impact, and so on. The total distance travelled by the ball till it comes to rest on the ground is: |
| A. | 2 m |
| B. | 5/3 m |
| C. | \[\frac{{{d}^{2}}+{{D}^{2}}}{8D}\] |
| D. | 5/4 m |
| Answer» C. \[\frac{{{d}^{2}}+{{D}^{2}}}{8D}\] | |
| 24. |
A jet engine works on the principle of: |
| A. | Conservation of energy |
| B. | Conservation of linear momentum |
| C. | Mass defect.........Binding energy |
| D. | Conservation of mass and momentum. |
| Answer» C. Mass defect.........Binding energy | |
| 25. |
A ballet of mass 1 kg is fired with a velocity of u m/s from a gun of mass 10 kg. The ratio of kinetic energies of bullet and gun is: |
| A. | 10 |
| B. | 11 |
| C. | 2 : 1 |
| D. | 0.1 |
| Answer» B. 11 | |
| 26. |
A thin circular ring of mass M and radius R is rotating about it axis with a constant angular velocity \[\omega .\] Two objects each of mass m are attached gently to the opposite ends of a diameter of the ring. The wheel now rotates with an angular velocity of: |
| A. | \[\frac{\omega M}{M+m}\] |
| B. | \[\frac{\omega (M+2M)}{M}\] |
| C. | \[100\,\,\text{N/m}{{\text{m}}^{\text{2}}}\] |
| D. | \[\frac{\omega M}{M+2m}\] |
| Answer» B. \[\frac{\omega (M+2M)}{M}\] | |
| 27. |
Match List-I (turbines) with List-II (classification) and select the correct answer using the codes given below the list: List-I List-II A. Parson's 1. Pressure compounded B. De Laval 2. Reaction C. Rateau 3. Simple impulse D. Curtis 4. Velocity compounded Codes: |
| A. | A\[\to \]3, B\[\to \]2, C\[\to \]1, D\[\to \]4 |
| B. | A\[\to \]2, B\[\to \]3, C\[\to \]4, D\[\to \]1 |
| C. | Change of velocity energy across the turbine to the total energy transfer. |
| D. | A\[\to \]3, B\[\to \]2, C\[\to \]4, D\[\to \]1 |
| Answer» D. A\[\to \]3, B\[\to \]2, C\[\to \]4, D\[\to \]1 | |
| 28. |
A spring of stiffness k is compressed by a length 'A' and a ball is placed on the top of it. When the spring is released the ball is seen to rise through a height h. When two such springs are kept one over the other, and the combination is compressed by same length X what is the height reached by the ball, kept on the combined springs when released? |
| A. | h/2 |
| B. | h |
| C. | \[4\times {{10}^{-\,4}}\] |
| D. | 2h |
| Answer» B. h | |
| 29. |
Electric lift is moving downwards with an acceleration of g/3 the vertical force between a passenger in the lift and its floor is equal to: |
| A. | 2/3rd of the passenger's weight |
| B. | 3/4th of the passenger's weight |
| C. | 1 and 4 |
| D. | 4/3 times the passenger's weight |
| Answer» B. 3/4th of the passenger's weight | |
| 30. |
An elevator weighing 100 kN attains an upward velocity of 4 m/s in two seconds with uniform acceleration. The tension in the cable will be approximately: |
| A. | 30 Kn |
| B. | 100 kN |
| C. | 19/27 |
| D. | 200 kN. |
| Answer» B. 100 kN | |
| 31. |
A wheel of mass m and radius r is in accelerated rolling motion without slip under a steady axle torque T. If the coefficient of kinetic friction is m, the friction from the ground on the wheel is: |
| A. | \[\mu mg\] |
| B. | T/r |
| C. | \[320/\sqrt{3}\,\text{m/s}\] |
| D. | None of the above |
| Answer» B. T/r | |
| 32. |
Two particles of same mass are moving with same speed on circular paths of radii r, and \[{{r}_{2}}.\] The ratio of their centripetal forces would be: |
| A. | \[{{r}_{2}}/{{r}_{1}}\] |
| B. | \[\sqrt{({{r}_{2}}/{{r}_{1}})}\] |
| C. | Lower at the hub and tip but different from the mean section |
| D. | \[{{({{r}_{1}}/{{r}_{2}})}^{2}}\] |
| Answer» E. | |
| 33. |
A box rests in the rear of a truck moving with a deceleration of \[2\,\,\text{m/}{{\text{s}}^{\text{2}}}.\] To prevent the box from sliding, the approximate value of static coefficient of friction between the box and the bed of the truck should be: |
| A. | 0.1 |
| B. | 0.2 |
| C. | \[\frac{1}{3}\] |
| D. | 0.4 |
| Answer» C. \[\frac{1}{3}\] | |
| 34. |
A person, carrying on his head a jewellery box of weight W jumped down from the third story of a building. Before touching the ground, he will feel a load of magnitude: |
| A. | Zero |
| B. | \[\frac{W}{2}\] |
| C. | 1 and 3 |
| D. | infinity |
| Answer» B. \[\frac{W}{2}\] | |
| 35. |
D Alemberts principle is used to: |
| A. | Solve static problems |
| B. | Solve kinematics problems |
| C. | Torque |
| D. | Solve elasticity problems |
| Answer» D. Solve elasticity problems | |
| 36. |
An elevator weighing 10 kN attains an upward velocity of 5 m/s in 2s with uniform acceleration. The tension in the supporting rope is: |
| A. | 3.75 kN |
| B. | 625 kN |
| C. | Only if the total work done by the particle in moving around in a closed trajectory is zero |
| D. | 1, 2.55 kN |
| Answer» E. | |
| 37. |
A man wishes to move a heavy block resting on a rough floor. How he can do it with minimum effort? |
| A. | By pulling with a rope |
| B. | By pushing |
| C. | Ideal flow of water in a pipe |
| D. | Impossible to move |
| Answer» D. Impossible to move | |
| 38. |
There are two products A and B with the following characteristics: Product Demand Order cost (in Rs./order) Holding cost (in Rs./unit) A 100 100 4 B 400 100 1 The economic order quantities (EOQ) of product A and B will be in the ratio of: |
| A. | 1 : 1 |
| B. | 0.0430555555555556 |
| C. | No change |
| D. | 0.0472222222222222 |
| Answer» D. 0.0472222222222222 | |
| 39. |
Classifying items in A, B and C categories for selective control in inventory managements is done by arranging items in the decreasing order of: |
| A. | Total inventory costs |
| B. | item value |
| C. | 38% |
| D. | item demand |
| Answer» D. item demand | |
| 40. |
Match List-I with List-II and select the correct answer is using the codes given below the Lists: List-I (Elements of cost) List-II (nature of cost) A. Interest on capital 1. Variable B. Direct labour 2. Semi-variable C. Water and electricity 3. Fixed Codes: |
| A. | A\[\to \]3, B\[\to \]1, C\[\to \]2 |
| B. | A\[\to \]2, B\[\to \]1, C\[\to \]3 |
| C. | Twice the initial value |
| D. | A\[\to \]2, B\[\to \]3, C\[\to \]1 |
| Answer» E. | |
| 41. |
Which one of the following does not form a part of the direct cost of a component? |
| A. | Cost of special tooling used |
| B. | Cost of material used |
| C. | 1875 kW |
| D. | Wages of the labour actually involved. |
| Answer» B. Cost of material used | |
| 42. |
In the EOQ model, if the unit ordering cost is doubled, the EOQ |
| A. | Is halved |
| B. | Is doubled |
| C. | Sum of the kinetic and potential energies remains constant |
| D. | Decrease 1.414 times. |
| Answer» D. Decrease 1.414 times. | |
| 43. |
A company sells 14,000 units of its product. It has a variable cost of Rs. 15 per unit. Fixed cost Rs. 47,000 and the required profit is Rs. 23,000.Per unit product price (in Rs.) will be: |
| A. | 60 |
| B. | 40 |
| C. | Decreases |
| D. | 20 |
| Answer» E. | |
| 44. |
For the same internal diameter, wall thickness, material and internal pressure, the ratio of maximum stress, induced in a thin cylindrical and in a thin spherical pressure vessel will be: |
| A. | 2 |
| B. | \[\frac{1}{2}\] |
| C. | The velocity of both balls is (1/2) \[\sqrt{2}\,\,gh\] |
| D. | \[\frac{1}{4}\] |
| Answer» B. \[\frac{1}{2}\] | |
| 45. |
The energy released during the fission of one atom of Uranium-235 in million electron vote is about: |
| A. | 100 |
| B. | 200 |
| C. | 4/3 m |
| D. | 400 |
| Answer» C. 4/3 m | |
| 46. |
In comparison to rolling friction, the value of sliding friction will be: |
| A. | less |
| B. | more |
| C. | Conservation of mass |
| D. | double |
| Answer» C. Conservation of mass | |
| 47. |
During tensile testing for cast iron specimen, the stress ? strain curve shows : |
| A. | No yield point |
| B. | upper yield point only |
| C. | 1.1 |
| D. | Both upper and lower yield points |
| Answer» B. upper yield point only | |
| 48. |
Poisson's ratio generally depends on: |
| A. | Material of specimen |
| B. | Area of cross section |
| C. | A\[\to \]2, B\[\to \]3, C\[\to \]1, D\[\to \]4 |
| D. | None of these |
| Answer» B. Area of cross section | |
| 49. |
Streamlined shapes offers resistance against air flow or water flow, the magnitude of the resistance is : |
| A. | Least |
| B. | Maximum |
| C. | \[\sqrt{2}h\] |
| D. | Positive |
| Answer» B. Maximum | |
| 50. |
Equilibrium equations given for non - concurrent forces are given as: |
| A. | \[\varepsilon {{F}_{X}}=0,\,\,\varepsilon {{F}_{y}}=0,\,\,\varepsilon M=0\] |
| B. | \[\varepsilon {{F}_{X}}=0,\,\,\varepsilon {{F}_{y}}=0\] |
| C. | Passenger's weight |
| D. | None of these |
| Answer» B. \[\varepsilon {{F}_{X}}=0,\,\,\varepsilon {{F}_{y}}=0\] | |