GATE Mechanical Engineers Don’t Want You to See These 37 Questions and Answers!

GATE (Graduate Aptitude Test in Engineering) is one of the most popular exams for Engineering graduates in India. It tests the comprehensive understanding of various undergraduate subjects in Engineering.

The GATE Mechanical Engineering paper tests the conceptual knowledge and analytical abilities of students in major areas like Engineering Mechanics, Strength of Materials, Theory of Machines, Machine Design, Fluid Mechanics, Thermodynamics, Heat Transfer, Materials Engineering, Manufacturing Processes, Industrial Engineering etc.

Most Asked GATE questions and answers for Mechanical Engineering

Based on analysis of previous years’ papers and experiences shared by toppers, here are some of the most frequently asked questions and their answers in GATE Mechanical Engineering exam:

1. In a four-stroke petrol engine, the valves open and close how many times per cycle?

Ans: Intake valve opens twice and exhaust valve opens twice per cycle. So total 4 times.

2. During adiabatic process in an ideal gas, which property remains constant?

Ans: Entropy

3. What is the critical Reynolds number for flow through a pipe?

Ans: 2300

4. In a closed cycle, heat supplied to the system is equal to?

Ans: Net heat transfer i.e. Heat supplied – Heat rejected

5. What is the effect of increasing blade angle on the air screw characteristics?

Ans: It increases thrust and torque while decreasing efficiency

6. In a belt drive, if the belt starts slipping, which of the following tension remains unchanged?

Ans: Centrifugal tension

7. Splines are used to transmit power between:

Ans: Two parallel shafts

8. In a turning operation on lathe, the cutting speed increases if?

Ans: Depth of cut decreases

9. In facilitated diffusion across a membrane, solute transport happens:

Ans: Down the concentration gradient

10. In a simply supported beam with a point load at the center, maximum bending stress occurs at:

Ans: Under the load point

11. Hydrostatic force on a vertical plane surface submerged in liquid will be?

Ans: Equal to product of area, depth and density of liquid

12. Who proposed the theory of elasticity?

Ans: Hooke

13. Poisson’s ratio for rubber is close to?

Ans: 0.5

14. Governors are used to regulate:

Ans: Speed of engine shaft

15. Thermodynamic cycle in which heat addition and rejection take place at constant volume is?

Ans: Joule cycle

16. In a spring-mass system undergoing free vibrations, as damping increases, which of following decreases?

Ans: Amplitude

17. During adiabatic compression in a reciprocating compressor, work done on the gas is used to?

Ans: Increase its internal energy

18. The angle between velocity and acceleration of a particle executing SHM is:

Ans: 90 degrees

19. In a closed cycle, increase in internal energy is equal to:

Ans: Net heat added to the system

20. In a rectangular beam, maximum shear stress occurs at:

Ans: Neutral axis

21. Refrigeration effect is highest for which of the following refrigerants?

Ans: Ammonia

22. Force analysis is based on which law?

Ans: Newton’s second law

23. Reciprocating pumps are suitable for:

Ans: High pressure and low discharge applications

24. Efficiency of a perfect heat engine operating between 227°C and 127°C will be:

Ans: 0.5

25. Power transmitted by a shaft is maximum when:

Ans: Torque is maximum

26. In a closed cycle, increase in entropy is equal to:

Ans: Entropy transfer by heat addition

27. Material used for making gears is:

Ans: Cast iron

28. Cavitation in pumps can cause:

Ans: Damage to impeller and casing

29. Ratio of actual power output to theoretical power output in an IC engine is called:

Ans: Efficiency

30. Boyle’s law relates:

Ans: Pressure and Volume of gas at constant temperature

31. Types of fluid flow based on variation of flow velocity across pipe section are:

Ans: Laminar and Turbulent

32. Welding process used to join non-ferrous materials is:

Ans: Gas welding

33. In projectile motion under gravity, the path followed by the projectile is a:

Ans: Parabola

34. Fourier number represents:

Ans: Ratio of heat conduction rate to heat storage rate

35. Slenderness ratio of a column is:

Ans: Effective length/Least radius of gyration

36. Hydraulic turbines convert:

Ans: Potential energy of water into mechanical energy

37. Second law of thermodynamics deals with:

Ans: Direction of natural processes

Conclusion

This covers some of the most frequently asked questions from major topics in the GATE Mechanical Engineering exam. Preparing these questions and understanding the concepts thoroughly will help you perform well in the exam. All the best!