What is the purpose of using the factor of safety in machine design?
A Improve efficiency
B Prevent failure
C Reduce cost
D Increase weight
The factor of safety provides a margin between the maximum load a component can withstand and the actual load it is subjected to. This ensures that even in unforeseen conditions, the component will not fail, increasing reliability and safety.
What type of gear is commonly used to change the direction of motion?
A Spur gear
B Worm gear
C Helical gear
D Bevel gear
Bevel gears are used to change the direction of motion. They typically have a conical shape, allowing them to transmit motion between shafts that are at an angle to each other, often 90 degrees in many applications.
Which material is primarily used for making bearings in machine design?
A Bronze
B Cast iron
C Copper
D Aluminum
Bronze is commonly used for bearings due to its low friction, high wear resistance, and good corrosion resistance properties. These qualities make it ideal for applications where components need to move smoothly under load.
What is the main purpose of a clutch in a machine system?
A To reduce friction
B To control speed
C To connect parts
D To store energy
A clutch’s primary function is to engage or disengage two rotating shafts, allowing the transmission of power when needed. It is commonly used in vehicles and other machinery for controlling power transfer between components.
What is the main purpose of a fatigue analysis in machine design?
A Predict material behavior
B Design bearings
C Test material hardness
D Calculate load limits
Fatigue analysis predicts how materials behave under repeated or cyclic loading. It helps identify potential failure points that may not be evident under static loading conditions, ensuring long-term reliability and safety of the design.
Which type of welding joint is commonly used in machine design for joining two parts?
A T-joint
B Butt joint
C Corner joint
D Fillet joint
Fillet joints are commonly used in machine design to connect two parts at a right angle. They are easy to apply, provide a strong connection, and are widely used in structural and mechanical applications.
What does the term ‘shear stress’ refer to in mechanical components?
A Force along a bend
B Force per unit area
C Force parallel to the surface
D Force perpendicular to the surface
Shear stress refers to the force that acts parallel to the surface of a material, causing layers of the material to slide over each other. It is critical to understand this stress when designing components subject to sliding or cutting forces.
Which type of material is typically chosen for gears that need to handle high torque?
A Aluminum
B Steel
C Brass
D Plastic
Steel is often chosen for gears that need to handle high torque due to its high strength, wear resistance, and ability to withstand the forces involved. It provides durability and long life for mechanical components in high-stress environments.
What is the primary function of a shaft in machine design?
A To store energy
B To transfer motion
C To support components
D To reduce vibrations
A shaft is a rotating machine element designed to transmit torque and rotary motion between components. Shafts are fundamental in most mechanical systems, facilitating the movement of parts like gears, pulleys, and wheels.
What is the main advantage of using a spring in machine design?
A Stores energy
B Changes direction
C Reduces weight
D Transmits power
Springs are used to store energy when compressed or stretched. They release this energy when needed, making them vital in applications such as shock absorption, energy storage, and force regulation in mechanical systems.
Which of the following is a common method of analyzing stress in machine design?
A Kinematic analysis
B Stress-strain analysis
C Torsional analysis
D Fatigue analysis
Stress-strain analysis is used to evaluate the response of materials to applied loads. It helps determine how materials will deform under various stress levels and is essential for ensuring that components can withstand operational conditions without failure.
In machine design, what does the term ‘buckling’ refer to?
A Fracture under shear
B Fracture under tension
C Sudden deformation under compression
D Sudden deformation under torsion
Buckling occurs when a component experiences sudden failure due to compressive forces. This typically happens in slender structures like columns or beams, which deform laterally and may collapse under critical load levels.
What is the role of lubrication in machine components?
A Prevents fatigue
B Reduces wear
C Increases friction
D Increases stress
Lubrication reduces friction between moving parts, which decreases wear and prevents overheating. It also helps distribute heat evenly and extends the life of components by reducing the chances of component failure due to frictional forces.
Which of the following is a common failure mode under static loading conditions?
A Creep failure
B Fatigue failure
C Shear failure
D Tensile failure
Tensile failure occurs when a material fails due to forces attempting to elongate it. Under static loading conditions, tensile stress can exceed the material’s ultimate tensile strength, causing it to fracture or break.
What is the main benefit of using the finite element analysis (FEA) in machine design?
A Optimize material usage
B Improve aesthetics
C Simulate physical behavior
D Increase component weight
Finite element analysis (FEA) allows designers to simulate how components will behave under real-world conditions by dividing a structure into smaller elements. It helps predict stresses, deformations, and thermal effects, ensuring optimal design performance.
