Engineering Physics - Elastic Properties of Materials

It completely regains its original shape.

A plastic body remains in a deformed state and does not regain its original shape.

Tensile stress.

<p>Longitudinal stress acts along the length of the material, while shearing stress acts parallel to its surface.</p> Signup and view all the answers

<p>Stress is the internal resistive force to deformation per unit area.</p> Signup and view all the answers

<p>Stress is the internal force per unit area, while pressure is the external force applied per unit area.</p> Signup and view all the answers

<p>The two types are tensile stress and compressive stress.</p> Signup and view all the answers

<p>The restoring force is equal to the deforming force.</p> Signup and view all the answers

<p>Elasticity is the inherent property of a material that allows it to restore its original shape after the deforming forces are removed.</p> Signup and view all the answers

<p>A perfectly elastic body completely regains its original shape after the removal of deforming forces.</p> Signup and view all the answers

<p>Restoring forces are caused by the displacements of molecules from their original positions of stable equilibrium due to applied deforming forces.</p> Signup and view all the answers

<p>The three types of deformations are length, volume, and shape.</p> Signup and view all the answers

<p>A deforming force is a force that changes the shape of a body upon application.</p> Signup and view all the answers

<p>A perfectly plastic material does not regain any shape upon removal of deforming forces, whereas a partially elastic material regains some of its original shape.</p> Signup and view all the answers

<p>Intermolecular forces help maintain the stable equilibrium positions of molecules, allowing them to return to these positions after deformation.</p> Signup and view all the answers

<p>The arrangement of molecules in a solid determines the stability of equilibrium positions and the efficiency of restoring forces during deformation.</p> Signup and view all the answers

<p>Stress is developed internally within a material, while pressure is an external force exerted on an object.</p> Signup and view all the answers

<p>The proportional limit marks the range where stress remains directly proportional to strain, according to Hooke’s Law.</p> Signup and view all the answers

<p>At the yield point, the material begins to deform plastically, leading to permanent changes in shape.</p> Signup and view all the answers

<p>The three types of stress are tensile, compressive, and shear stress.</p> Signup and view all the answers

<p>Elastic modulus is the proportionality constant between stress and strain in the elastic region, indicating a material's stiffness.</p> Signup and view all the answers

<p>The ultimate stress point is where a material undergoes maximum stress before failure or fracture occurs.</p> Signup and view all the answers

<p>The upper yielding point is where initial yielding occurs, while the lower yielding point represents the stress level at which flow continues.</p> Signup and view all the answers

<p>Tensile strength is the maximum amount of stress a material can withstand before breaking.</p> Signup and view all the answers

<p>The fracture point is the point at which a material breaks due to impact force, and it is significant because it indicates the maximum stress a material can withstand.</p> Signup and view all the answers

<p>Heat conduction is the transfer of heat from a hotter region to a colder one without molecular movement. An example is frying vegetables in a pan.</p> Signup and view all the answers

<p>Thermal conductors easily transfer heat, whereas insulators do not conduct heat effectively.</p> Signup and view all the answers

<p>Convection is the transfer of heat in liquids and gases through the bulk movement of molecules. An example is heating milk in a pan.</p> Signup and view all the answers

<p>Radiation is the transfer of heat in the form of electromagnetic waves without requiring a medium.</p> Signup and view all the answers

<p>Radiation does not require a material medium to transfer heat, as it relies on electromagnetic waves.</p> Signup and view all the answers

<p>In convection, heat transfer occurs partly due to the actual movement of molecules or mass transfer.</p> Signup and view all the answers

<p>Both conduction and convection are modes of heat transfer that facilitate the movement of thermal energy.</p> Signup and view all the answers

<p>The Seebeck Effect is the generation of an electric potential across a temperature gradient in a thermocouple, proportional to the temperature difference.</p> Signup and view all the answers

<p>The Peltier Effect involves heating at one junction and cooling at another when an electric current flows through a thermocouple, allowing for temperature control in various applications.</p> Signup and view all the answers

<p>Temperature gradients cause electric current to flow in a material, enabling energy conversion between heat and electricity.</p> Signup and view all the answers

<p>The Wiedemann-Franz law relates electrical conductivity to thermal conductivity in metals, indicating that good conductors of electricity are also good conductors of heat.</p> Signup and view all the answers

<p>A thermocouple measures the voltage difference between two dissimilar materials at different temperatures to determine temperature differences.</p> Signup and view all the answers

<p>When there is a potential difference, it induces a temperature gradient within the material, demonstrating the reversible nature of the thermoelectric effect.</p> Signup and view all the answers

<p>Dissimilar conductors, often semiconductors, are used in thermoelectric devices due to their ability to create significant temperature gradients and voltage differences.</p> Signup and view all the answers

<p>One application is in waste heat recovery systems, where waste heat from engines or industrial processes is converted into usable electrical energy.</p> Signup and view all the answers

<p>The Thomson effect describes heat exchange in a conductor with a temperature gradient when electric current flows, linking the Seebeck and Peltier effects by showing the relationship between temperature, charge carriers, and electric fields.</p> Signup and view all the answers

<p>Free charge carriers in a conductor allow for diffusion from hot to cold regions, creating an electric field that counters further diffusion due to the temperature gradient.</p> Signup and view all the answers

<p>Thermoelectric generators and digital thermometers are significant applications of thermoelectricity.</p> Signup and view all the answers

<p>The Debye model derives specific heat by considering phonon modes in solids, explaining how at low temperatures, specific heat behaves as $C_V \propto T^3$.</p> Signup and view all the answers

<p>A Poisson's ratio of $\sigma = 0.5$ indicates that the lateral strain is equal to half of the longitudinal strain in the cylinder upon applying stress.</p> Signup and view all the answers

<p>The elastic potential energy density is given by the formula $u = \frac{1}{2} \times \text{Stress} \times \text{Strain}$, illustrating how energy is stored in deformed materials.</p> Signup and view all the answers

<p>When a spring with a force constant $k$ is cut into four equal parts, the new force constant for each part becomes $4k$.</p> Signup and view all the answers

<p>The work done on a wire stretched by amount $x$ is given by $W = \frac{Y A x^2}{2L}$, linking Young's modulus to work and deformation.</p> Signup and view all the answers