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

The property of a body to return to its original shape after a deforming force is removed.

A body that completely regains its original shape after a deforming force is removed.

A body that does not regain its original shape after a deforming force is removed.

A force that changes the shape of a body.

The internal force that opposes the deformation caused by a deforming force.

Forces between molecules that hold a solid together in shape.

Arranged in a specific pattern in a solid.

The state where the forces acting on a molecule balance each other out.

A body that completely returns to its original shape after a deforming force is removed.

A body that does not return to its original shape after a deforming force is removed.

Stress that occurs when an external force increases the length of an object.

Stress that occurs when an external force decreases the length of an object.

Internal resistive force to deformation per unit area.

Force applied per unit area.

Stress caused by forces that change the length of an object.

Stress is internal resistance to deformation, while pressure is the force per unit area applied from the outside.

Stress can be tensile, compressive, or shear.

Strain in a material is directly proportional to stress over a certain strain rate.

The point on a stress-strain curve where stress and strain are directly proportional to one another.

The point on the stress-strain curve beyond which the material will no longer return to its original size after the force is removed.

Point where material begins to deform plastically.

The maximum stress a material can withstand before failure.

The point on a stress-strain curve where a material breaks or fractures due to applied force.

Transfer of heat through direct contact between molecules, without any movement of the material itself.

A material that allows heat to flow easily through it.

A material that resists the flow of heat.

Transfer of heat through the movement of fluids (liquids and gases) from a hotter region to a colder region.

Transfer of heat through electromagnetic waves, without needing a medium.

Conduction involves heat transfer through direct contact between molecules, while convection involves heat transfer through the movement of fluids.

Microwaves use electromagnetic radiation to directly heat the food molecules, without needing a medium.

When an electric current flows through a conductor with a temperature gradient, heat is exchanged with the surroundings to maintain the original temperature gradient.

A device that converts heat energy directly into electrical energy using the Seebeck effect.

Quantized packets of vibrational energy in a solid material.

The amount of heat required to raise the temperature of 1 gram of a substance by 1 degree Celsius.

A model that explains the specific heat capacity of solids based on the assumption that all atoms vibrate with the same frequency.

A more refined model that accounts for the range of frequencies of atomic vibrations in a solid.

Mathematical descriptions of the distribution of energy among particles in a system.

The Debye model considers the range of frequencies of atomic vibrations, offering a better representation of specific heat capacity at different temperatures, while the Einstein model assumes a single frequency.

The ability of a material to transfer heat through it. Materials with high thermal conductivity transfer heat quickly, while those with low thermal conductivity are good insulators.

The ability of a material to conduct electricity. Materials with high electrical conductivity allow electrons to flow easily, while those with low electrical conductivity resist the flow of electrons.

A relationship between the thermal conductivity and electrical conductivity of a material. It states that good electrical conductors are also good thermal conductors.

The conversion of temperature differences into electrical voltage and vice versa. This effect is used in thermocouples and Peltier devices.

This effect describes how a temperature difference across two dissimilar materials creates an electrical voltage.

This effect describes the heating or cooling at the junction of two different materials when an electric current is passed through them.

Electrical conductivity describes how well a material allows the flow of electrical current, while thermal conductivity describes how well a material allows the transfer of heat energy.

The Seebeck effect is used to create thermocouples, which are devices that measure temperature differences by generating a small voltage.