What is a source?  Basically a source is a device that supplies electrical energy like batteries, generators. 

What is an electrical circuit?  Basically an electrical circuit is a closed path through which current flows. All electrical circuits are electrical networks.

What is an electrical network?  Basically any arrangement of electrical power sources and circuit components is known as electrical network. And electrical power sources can be batteries and generators. Circuit elements are resistance (R), inductance (L), and capacitance (C). 

What is stress?  Stress is basically the internal resistance of an object to a force applied to a unit area. And that's the scale of the tensor. A tensor also has magnitude, direction, and a plane with respect to which the stress is defined. Basically it is not the same at all points. It changes angle and direction. Basically the force creating surface tension can act at any angle and direction. The normal stress is the component perpendicular to the plane of the surface and the shear stress is the component perpendicular to the plane of the surface. And it can be either compressive or tensile. Compression is positive normal stress and tension is negative normal stress. Commonly Stress is used for solid materials and is expressed in MPa/GPa. It has no measuring device but it can be measured.

What is pressure?  Pressure is basically Force / Area and is the magnitude of an external force applied to a unit area. A scalar measure of pressure has only magnitude in it. Pressure is basically equal at all points and in all directions. If there is pressure on a surface, it always acts perpendicular to the surface. And this is considered a special case of stress. It is always compressed and is used for fluids, liquids and gases. It is usually specified in N/m^2. And it is commonly measured by various measuring devices like manometer, bourdon tube, diaphragm etc.

What is a Parallel Circuit? Parallel Circuit  Basically a parallel circuit is one in which the components are directly connected to each other. Each component in a parallel circuit operates at the same voltage as the source. In other words, the voltage across different components in a parallel circuit is the same. [ Vt = V1 = V2 = V3…= Vn ]. And in this circuit two or more paths are available for current flow. The number of current paths is equal to the number of parallel elements. And two or more paths are available for current flow in this circuit. The number of current paths is equal to the number of parallel elements. In a parallel circuit the current is varied and mixed. [ To = I1 + I2 + I3…+In]. In a resistive parallel circuit, the total resistance is less than any of the individual resistances. [ Rt = 1 / (1/R1 + 1/R2+ . . . 1/Rn) ]. In an inductive parallel circuit, the total inductance is less than any individual inductance. [ Lt = 1 / (1/L1 + 1/L2+ . . . 1/Ln)]. and capacitiv

What is a Series Circuit? Series Circuit  Basically this circuit consists of a series of elements connected one after the other. And it is also called one to one connection or cascade connection. A circuit short in series or a break at any point in the circuit causes the entire circuit to become unusable. The total voltage applied to a series circuit is distributed in a series of voltage drops across the various components of the circuit. In other words, the sum of the voltage drops across the individual components in a series circuit equals the total applied voltage. [ Vt = V1 + V2 + V3…+Vn ]. There is only one path available for current flow in this circuit and the current through all the elements in a series circuit is the same. [ It = I1 = I2 =I3 … = In ]. Basically in a resistive series circuit, the total resistance is equal to the sum of the individual resistances. [ Rt =  R1 + R2 + R3…+Rn ]. In an inductive series circuit, the total inductance is equal to the sum of the individu

What is a  Instrument Transformer? Instrument Transformers   Basically this Transformers used in conjunction with measuring instruments like current, voltage, power, frequency, power factor are called instrument transformers and it is used in AC system. And these transformers are used to provide isolation between the power circuit and the control circuit. These transformers are also used in conjunction with protective relays. Instrument transformers are of two types. they are, A current transformer measures high current and a potential transformer measures high voltage. Instrument transformers are also used with protective relays for power system protection. Commonly instrument transformers are used to step down AC system voltage and current. And this voltage and current level of the power system is very high. Designing measuring devices to measure such high levels of voltage and current is very difficult and expensive. The measuring instrument is generally designed for 5 A and 110 V.

What is Optical Fiber and it's types ?  Optical Fiber Basically an optical fiber is a thin strand of glass or plastic that acts as a transmission medium through which information is transmitted. And optical fiber is a dielectric waveguide that operates at optical frequencies (10^13 to 10^16 Hz) and transfers information in the form of light through the mechanism of total internal reflection. Also an optical fiber has a central core surrounded by a cladding layer. Types of optical fiber  Step index fibers, graded index fibers, single mode fibers, multimode fibers, glass, plastic clad fibers and all plastic fibers are basically common types of optical fibers. And the step index and graded index are based on the fiber refractive index profile. Single mode and multimode fiber is based on the number of modes. Glass, plastic clothing and all plastics are fiber based materials. Related Articles Step Index Fiber  Graded Index Optical Fiber Single Mode Fibers Multimode Fibers Glass Fibers 

What is Multi Mode Fiber?  Multi Mode Fiber  Basically multimode fiber, more than one mode can be transmitted through the fiber. Like multimode graded index fiber and multimode step index fiber. The core diameter of multi mode fiber is wide (>50µm) and the refractive index between core and cladding is large. Multimode fibers can be made using step index or graded index fibers, as the core is wider. And LED and LASER are used as optical sources. Multi-mode fibers are subject to signal distortion due to multimode dispersion and material dispersion. It has large dispersion and attenuation limits its application for short distance communication. These fibers are used in local area networks. And it is easy to insert light into these fibers and connect two fibers. Multimode fibers are relatively easy to fabricate and are not expensive.

What is Single Mode Fiber? Single Mode Fibers  Basically single mode fibers have only one path for transmission i.e. only one mode can travel through it. And this core diameter is narrow (2 to 10µm). Single mode fibers refractive index difference between core and cladding is very small. Also single mode fibers are always step indexed because the core is narrow which cannot be graded indexed. Only lasers can be used as optical sources. Dispersion does not occur as there is no degradation of the signal during its propagation through the fiber. and are suitable for long distance communication due to its high data carrying capacity. And fabrication is very difficult to make expensive. It is very difficult to pass light between these fibers and connect two fibers.

What are Graded Index Optical Fiber ? Graded Index Optical Fiber Basically the graded index fiber refractive index of the core is not constant. And this core refractive index changes as a function of radial distance from the center of the fiber. And graded index fiber is simply multimode graded index fiber. The graded index fiber ri is maximum along the axis of the core and decreases from the core to the cladding. And this diameter of core is about 50µm in multimode fiber. Graded index fiber means light rays are given a helical path to pass through the graded index fiber. The rays are named as Skew Rays. And the self-focusing effect reduces this fiber loss and pulse distortion. And the capacity to carry information increases.

What is the Step Index Optical Fiber ?  Step Index Optical Fiber Basically a step index fiber in which the refractive index of the core is uniform throughout the length of the fiber. and step index The fiber refractive index undergoes an abrupt change (such as a step function) at the cladding boundary. And it has single mode as well as multimode step index fiber. And this diameter of the core is about 50 to 200µm in case of multimode fiber and 10µm in case of single mode fiber. The step index fiber ri of the cladding is slightly lower than that of the core. These fiber rays of light are given a path confined to the plane of the fiber core axis as they pass through the step index fiber. The rays are called meridional rays. Step index Fiber loss and pulse distortion are high Information carrying capacity is low.

What are the functions of valves in a piping system?  Essentially, valves play a vital role in increasing efficiency, improving quality control and ensuring process safety and reliability. A primary consideration in valve selection is the desired function of the valve. Valves are included in piping systems for one or more of the following reasons Starting or stopping fluid flow.  Throttling flow rates in piping systems.  Pressure regulation.  Regulation of fluid temperature in piping systems.  Redirecting flow from one path to another. Restricting flow to balance the system or prevent overpressure.  Prevent reverse flow of fluid.  Stopping the flow if the system fails.  Improving safety by reducing pressure or vacuum in a piping system. Basically, a valve is a mechanical device used in fluid systems to direct, separate, mix, or control fluid flow or pressure by improving passage through pipes. Normally when the valve is in the open position, the passage flows at a lower pressure than w

What are All Plastic Optical Fibers? All Plastic Fibers  Basically all plastic fibers have a plastic core and cladding. And it reduces the need for a buffer jacket for plastic core and cladding fiber protection and has high loss and great mechanical strength. and are used for low-cost links of very short distances.