Introduction to Mechanical Engineering MCQs (Part-3)
What is the primary function of a gearbox in a mechanical system?
A Convert heat
B Increase torque
C Measure speed
D Store energy
A gearbox is used to adjust the torque and speed between connected components. It reduces or increases the speed of a shaft while enhancing torque, making it crucial in applications like automotive systems, conveyors, and machinery where variable power output is needed.
Which type of force is responsible for the deformation of materials?
A Gravity
B Friction
C Vibration
D Tension
Tension is a force that attempts to elongate a material. When the force exceeds the material’s tensile strength, it causes deformation or failure. It is important to consider tension when designing structural components like beams, cables, and shafts.
Which engineering branch focuses on the design and manufacture of tools?
A Civil
B Electrical
C Mechanical
D Aerospace
Mechanical engineering is primarily concerned with the design, analysis, and manufacture of tools and machines. It applies principles of physics and materials science to create systems that involve movement, energy conversion, and mechanical work.
What does the term “mechanical advantage” refer to in machines?
A Increased force
B Decreased size
C Increased speed
D Increased energy
Mechanical advantage refers to the ratio of the output force to the input force in a mechanical system. It describes how machines like levers, pulleys, and gears amplify force, allowing tasks to be completed with less effort.
What is the function of a compressor in mechanical systems?
A Decrease temperature
B Increase pressure
C Reduce friction
D Increase speed
A compressor increases the pressure of a gas or air by reducing its volume. It is crucial in systems like refrigeration, air conditioning, and internal combustion engines, where compressed air is used for energy storage or mechanical work.
What type of energy is primarily used in thermodynamics?
A Kinetic
B Mechanical
C Electrical
D Heat
Thermodynamics focuses on the study of heat transfer, energy conversion, and the laws governing these processes. Heat is the primary form of energy involved in thermodynamic cycles, such as in engines, refrigerators, and heat pumps.
What is the purpose of using lubrication in machines?
A Reduce wear
B Control temperature
C Prevent rust
D Store energy
Lubrication reduces friction between moving parts, minimizing wear and tear. It helps prevent overheating, extends the lifespan of machine components, and improves efficiency in engines, gears, and bearings by providing a protective film between surfaces.
Which of these is a primary function of a shaft in mechanical systems?
A Convert heat
B Store energy
C Transmit power
D Measure speed
A shaft transmits mechanical power from one component to another, typically from a motor to a machine or vehicle. It must withstand rotational forces, and its strength, durability, and alignment are key for smooth operation and energy efficiency.
What is the main purpose of vibration damping in machinery?
A Enhance speed
B Store energy
C Prevent damage
D Reduce noise
Vibration damping is used to absorb or reduce vibrations in mechanical systems. This helps prevent mechanical damage, wear, and fatigue. It is crucial in machinery like motors, turbines, and vehicles to ensure smooth operation and extend the lifespan of components.
Which process is used to create solid parts from molten metal?
A Machining
B Welding
C Casting
D Forging
Casting is a manufacturing process where molten metal is poured into a mold to create solid parts. It is widely used to form complex shapes and is essential in producing components such as engine blocks, turbine blades, and machine housings.
What is the primary use of pneumatic systems in mechanical engineering?
A Control pressure
B Power generation
C Fluid filtration
D Heat transfer
Pneumatic systems use compressed air to transmit and control energy. They are commonly used for automation in tools, machinery, and control systems. By varying air pressure, pneumatic systems control movement, force, and precision in various applications.
What is a key characteristic of an ideal fluid in fluid mechanics?
A Compressible
B High density
C High pressure
D Non-viscous
An ideal fluid has no viscosity, meaning it does not resist flow. While no real fluid is truly ideal, this concept is used to simplify calculations and understand fluid dynamics, helping in the design of pipes, pumps, and turbines.
In mechanical systems, what is the function of a pulley?
A Change direction
B Compress air
C Increase speed
D Store energy
A pulley is used to change the direction of force applied in mechanical systems. It can also be used to lift loads, transmit power, or provide mechanical advantage, especially when combined with ropes or belts in cranes, elevators, and other machinery.
What does “stress concentration” refer to in materials?
A Material strength
B Force buildup
C Energy loss
D Force distribution
Stress concentration occurs when a material experiences localized increases in stress, often due to irregularities such as notches, cracks, or sharp corners. These points are vulnerable to failure, so design engineers aim to minimize stress concentration in structural components.
Which energy conversion happens in a heat engine?
A Potential to kinetic
B Kinetic to thermal
C Heat to mechanical
D Electrical to mechanical
A heat engine converts thermal energy (heat) into mechanical energy. This process typically involves a fuel source that produces heat to expand a gas, which in turn does mechanical work by moving a piston or turbine, as seen in car engines and power plants.