What does the term “kinematic pair” refer to in mechanism design?
A A fixed link
B A pair of links
C A rotating link
D A movable joint
A kinematic pair refers to a connection between two links in a mechanism that allows relative motion. The pair can be classified based on the type of motion allowed (e.g., sliding or rotating).
In a simple harmonic motion, the restoring force is directly proportional to:
A Angular velocity
B Velocity
C Displacement
D Acceleration
In simple harmonic motion (SHM), the restoring force is directly proportional to the displacement from the equilibrium position. This relationship is described by Hooke’s Law, which governs oscillatory motion.
What is the primary function of a universal joint in mechanical systems?
A Reduce vibrations
B Transfer linear motion
C Control speed
D Transfer rotational motion
A universal joint, also known as a U-joint, is used to transfer rotational motion between shafts that are not in line with each other. It is widely used in automotive drivetrains to accommodate angular changes.
What is the main purpose of using a harmonic balancer in an engine?
A Reduce vibration
B Increase speed
C Control fuel efficiency
D Increase torque
A harmonic balancer is used to reduce the vibrations caused by the engine’s rotational forces. It absorbs and dampens the harmonic vibrations, thereby protecting engine components and improving engine performance.
What is the significance of a gear’s pitch in a gear system?
A Gear alignment
B Tooth size
C Speed reduction
D Gear ratio
The pitch of a gear refers to the number of teeth per unit length along its circumference. It determines the size of the teeth and plays a crucial role in ensuring proper meshing with other gears in a system.
What is the function of a flywheel in an engine?
A Increase pressure
B Control emissions
C Store energy
D Regulate fuel
The flywheel stores rotational energy, helping smooth out fluctuations in speed. This function is crucial in engines to maintain consistent output and prevent abrupt changes in speed, enhancing performance.
Which of the following is an example of a non-positive drive mechanism?
A Belt drive
B Clutch drive
C Chain drive
D Gear drive
A belt drive is a non-positive drive mechanism, meaning that it does not provide a fixed connection between the driving and driven elements. The power transmission relies on friction, making it susceptible to slippage.
What is the effect of increasing the diameter of a flywheel?
A Reduces torque
B Reduces energy storage
C Increases speed variation
D Increases energy storage
Increasing the diameter of a flywheel increases its rotational inertia, allowing it to store more energy. This helps in stabilizing the rotational speed of machines by absorbing and releasing energy during operation.
What is the main function of a camshaft in an engine?
A Increase torque
B Operate pistons
C Operate valves
D Control fuel supply
A camshaft is used in internal combustion engines to operate the intake and exhaust valves. The cams on the shaft push against lifters, causing the valves to open and close at the correct times.
What is the purpose of a gear ratio in a mechanical system?
A Increase power
B Control torque
C Change rotational speed
D Reduce friction
The gear ratio determines the relationship between the input and output speeds of a gear system. By adjusting the ratio, the system can either increase or decrease the rotational speed while affecting torque.
What does the term “dynamic force” refer to in machine dynamics?
A Force due to motion
B Force in equilibrium
C Force caused by acceleration
D Force due to static load
Dynamic forces are forces that arise due to the motion of components in a machine. These forces are time-varying and must be considered when analyzing the behavior of moving parts, such as in the case of vibration and load changes.
What is a torque analysis primarily used for in mechanical design?
A To calculate energy loss
B To determine load distribution
C To measure heat transfer
D To analyze rotational forces
Torque analysis focuses on understanding the rotational forces acting within a system. It helps in determining how these forces are transferred and balanced across components, ensuring the system operates smoothly and safely.
Which of the following elements is essential in the design of a robotic arm mechanism?
A Governors
B Cams
C Linkages
D Flywheels
Linkages are essential in robotic arms as they create the mechanical connections needed to produce precise motions. The design of these linkages allows the arm to move in multiple directions to perform complex tasks.
What does a velocity diagram represent in mechanism analysis?
A Speed of links
B Energy consumption
C Forces on a body
D Torque distribution
A velocity diagram is used to graphically represent the speeds and directions of moving components in a mechanism. It provides insights into how velocity varies through different parts of the system.
What is the effect of reducing the number of teeth on a gear?
A Increases gear ratio
B Decreases torque
C Decreases speed
D Increases torque
Reducing the number of teeth on a gear decreases its torque transmission capacity. Fewer teeth engage in the meshing process, leading to a reduction in the output torque relative to the input.
