Kinematic Pairs Classification Quiz

A lower pair is defined as having surface contact between two elements, where one slides over the other during relative motion.

A higher pair is characterized by line or point contact between two elements, with motion that is partly turning and partly sliding.

Self-closed pairs are mechanically connected to allow required relative motion, while force-closed pairs are not mechanically connected and rely on external forces to maintain contact.

<p>Completely constrained motion occurs when the motion between a pair is limited to a definite direction, regardless of the force applied.</p> Signup and view all the answers

<p>An example of a lower pair is a sliding pair, such as the motion between the piston and cylinder in an engine.</p> Signup and view all the answers

<p>Mechanical systems like gear systems, belt drives, and roller bearings can utilize higher pairs.</p> Signup and view all the answers

<p>A force-closed pair is used in a cam and follower setup, where springs and gravity keep the two in contact.</p> Signup and view all the answers

<p>External forces are crucial in force-closed pairs as they maintain contact between the elements without mechanical connection.</p> Signup and view all the answers

<p>The number of degrees of freedom for a four bar chain is one.</p> Signup and view all the answers

<p>A five bar chain possesses two degrees of freedom.</p> Signup and view all the answers

<p>'Degrees of freedom' refers to the number of input parameters that must be independently controlled to utilize the mechanism.</p> Signup and view all the answers

<p>When connected to another link, it typically reduces to one degree of freedom due to constraints imposed by the joint.</p> Signup and view all the answers

<p>The coordinates x and y, along with the inclination Θ of the link, are used to specify the position of a point on a moving link.</p> Signup and view all the answers

<p>The fixed link serves as the reference against which the positions of other links are defined.</p> Signup and view all the answers

<p>Understanding degrees of freedom is crucial for optimizing mechanism performance and ensuring that it can achieve its intended functions.</p> Signup and view all the answers

<p>Adding a joint generally reduces the degrees of freedom of the connected link due to imposed constraints.</p> Signup and view all the answers

<p>Inversion of mechanism refers to the process of obtaining different mechanisms by fixing different links in a kinematic chain.</p> Signup and view all the answers

<p>The three important types are the four bar chain, single slider crank chain, and double slider crank chain.</p> Signup and view all the answers

<p>The beam engine converts rotary motion into reciprocating motion using a crank and lever mechanism.</p> Signup and view all the answers

<p>Links AD and BC act as cranks that transmit rotary motion to the respective wheels.</p> Signup and view all the answers

<p>Link CD serves as a coupling rod that maintains a constant center-to-center distance between the wheels.</p> Signup and view all the answers

<p>Watt's indicator mechanism functions as a double lever mechanism that measures the performance of steam engines.</p> Signup and view all the answers

<p>A four bar chain is a kinematic chain consisting of four links that allows for a wide range of motions.</p> Signup and view all the answers

<p>A double slider crank chain converts linear motion to rotary motion using two sliding pairs.</p> Signup and view all the answers

<p>An unconstrained chain is one where the relative motion between links is not completely constrained, leading to a less predictable movement.</p> Signup and view all the answers

<p>Five links.</p> Signup and view all the answers

<p>By verifying that the left hand side equals the right hand side of the relevant equations for the number of links.</p> Signup and view all the answers

<p>The equation is $L = 2P - 4$ for the number of links and pairs.</p> Signup and view all the answers

<p>Yes, it satisfies the equations indicating it is a kinematic chain.</p> Signup and view all the answers

<p>More than four links.</p> Signup and view all the answers

<p>A simple mechanism consists of four links.</p> Signup and view all the answers

<p>To withstand both static and kinetic forces safely during operation.</p> Signup and view all the answers

<p>Completely constrained motion occurs when the motion of a pair is limited to a definite direction, such as a piston in a cylinder.</p> Signup and view all the answers

<p>An example of incompletely constrained motion is a circular bar or shaft in a circular hole that can either rotate or slide.</p> Signup and view all the answers

<p>Successfully constrained motion requires external means to prevent undesired movements, while incompletely constrained motion allows for more than one type of movement without restriction.</p> Signup and view all the answers

<p>The motion of a square rod in a square hole is an example of completely constrained motion.</p> Signup and view all the answers

<p>The piston in a steam engine undergoes completely constrained motion, reciprocating within the cylinder.</p> Signup and view all the answers

<p>The I.C. engine valve is retained on its seat by a spring, preventing any upward movement, which illustrates successfully constrained motion.</p> Signup and view all the answers

<p>Impressed force in incompletely constrained motion can alter the direction of relative motion between the two pairs.</p> Signup and view all the answers

<p>Yes, a shaft in a footstep bearing can exhibit both incompletely constrained motion when it rotates and successfully constrained motion when prevented from moving upward.</p> Signup and view all the answers