Mechanical Engineering GATE 2025 Questions with Answer

Ques 53 Solid Mechanics

An isotropic brittle material is tested in the universal testing machine. The stress-strain diagram for the material shows a bi-linear elastic behavior as shown in the figure given below. The strain energy density is ______ MJ m^-3 (rounded off to 2 decimal places).

Ques 54 Theory of Machines

A rigid circular disc of radius r (in m) is rolling without slipping on a flat surface as shown in the figure below. The angular velocity of the disc is ω (in rad s^-1). The velocities (in m s^-1) at points O and A, respectively, are

Ques 55 Theory of Machines

In the context of balancing of rotating and reciprocating masses, which one of the following options is true?

Ques 56 Theory of Machines

An offset slider-crank mechanism is shown in the figure below. The length of the stroke of the slider is ______ mm (rounded off to nearest integer).

Ques 57 Thermodynamics

Let a spherical block of ice at -7°C be exposed to atmospheric air at 30°C with the gravitational direction as shown in the figure below. What will be the overall direction of air flow in this situation?

Ques 58 Thermodynamics

Air inside a rigid, thermally-insulated tank undergoes stirring as shown in the figure below. Which one of the following options is correct?

Ques 59 Thermodynamics

In a psychrometric chart, one axis represents dry-bulb temperature. The axis, that is perpendicular to the dry-bulb temperature axis, represents

Ques 60 Thermodynamics

The thermal efficiency of an ideal air-standard Otto cycle is 0.5. The value of specific heat ratio of air is 1.4. The compression ratio of the cycle is ______ (rounded off to 1 decimal place).

Ques 61 Thermodynamics

A thermal power plant is running with no reheat or regeneration. The specific enthalpy and specific entropy of steam at the turbine inlet are 3344 kJ kg^-1 and 6.5 kJ kg^-1K^-1 respectively. The turbine isentropic efficiency is 0.9, and the mass flow rate of steam at the turbine inlet is 102 kg s^-1. The turbine power output is ______ MW (rounded off to 1 decimal place).
Properties of saturated liquid and saturated vapor at turbine exit pressure

Ques 62 Thermodynamics

A thermodynamically closed system contains 1 kg of hydrogen. The system undergoes a reversible polytropic process with polytropic index 1.3. The work output during the process is 400 kJ. During the process, hydrogen behaves as an ideal gas with constant specific heats. The absolute value of heat transfer during the process is ______ kJ (rounded off to 1 decimal place).
Specific heat of hydrogen at constant pressure =14.56 kJ kg^-1K^-1
Specific heat of hydrogen at constant volume =10.4 kJ kg^-1K^-1

Ques 63 Thermodynamics

A heat pump, operating in reversed Carnot cycle, maintains a steady air temperature of 300 K inside an auditorium. The heat pump receives heat from the ambient air. The ambient air temperature is 280 K. Heat loss from the auditorium is 15 kW. The power consumption of the heat pump is ______ kW (rounded off to 2 decimal places).

Ques 64 Vibrations

A block of mass 1 kg connected to a spring of stiffness 10 N m^-1 is operating in a viscous medium such that the damping ratio (or damping factor) is equal to the ratio of the damped frequency to the natural frequency. The magnitude of the damping ratio for this system is ______ (rounded off to 2 decimal places).

Ques 65 Vibrations

The system shown in the figure below consists of a cantilever beam (with flexural rigidity EI and negligible mass), a spring (with spring constant K and negligible mass) and a block of mass m. Assuming a lumped parameter model for the system, the fundamental natural frequency (ω_n) of the system is