Definition: A varistor is a 2 terminal semiconductor device that protects the electrical and electronic devices from overvoltage transients. Its resistance is dependent on the applied input voltage. The word varistor is formed by the combining variable and resistor. It is also known as voltage-dependent resistor, VDR whose resistance changes automatically with the corresponding change in…
Read moreDefinition: A semiconductor device that generates coherent light of high intensity is known as laser diode. LASER is an abbreviation for Light Amplification by Stimulated Emission of Radiation. Stimulated emission is the basis of working of a laser diode. Laser diode is similar to LED, however, different from LED, the PN junction of laser diode…
Read moreDefinition: A special type of PN junction device that generates current when exposed to light is known as Photodiode. It is also known as photodetector or photosensor. It operates in reverse biased mode and converts light energy into electrical energy. The figure below shows the symbolic representation of a photodiode: Principle of Photodiode It works…
Read moreOne of the major difference between the transducer and the inverse transducer is that the transducer changes the non-electrical quantity into an electrical quantity while the inverse transducer changes the electrical quantity into the non-electrical quantity. The other differences between the transducer and inverse transducer are shown below in the comparison chart. The control action…
Read moreOne of the significant difference between the AC and DC bridge is that the AC bridge is used for measuring the unknown impedance of the circuit whereas the DC bridge is used for measuring the unknown resistance of the circuit. The other differences between the AC and DC bridge are shown below in the comparison…
Read moreDefinition: The instrument whose working depends on the principle of attraction or repulsion of electrodes that carry electrical charges such type of instrument is known as the electrostatic instrument. In other words, the instrument which uses the static electric field for producing the deflecting torque is known as the electrostatic instrument. The electrostatic instrument is…
Read moreDefinition: The synchroscope is a device which shows the correct instant at which the two systems are synchronised. The terms ‘synchronize’ means the machines of equal frequency and voltage are operating parallel to each other. The synchroscope consists the two-phase wound stator and rotor. The alternators provide the two-phase supply to the synchroscope. If any…
Read moreDefinition: The temperature transducer converts the thermal energy into a physical quantity likes the displacement, pressure and electrical signal etc. It is an electrical device used for automatic measuring of temperature. The main principle of the temperature transducer is to measure the heat and transfer the information after converting it into the readable form. The…
Read moreOne of the significant difference between the moving iron and moving coil instrument is that in moving iron instrument, the soft iron system is used for measuring mechanism. Whereas in moving coil instrument the conductor coil is used for DC measurement. The other differences between the moving iron and moving coil instrument are shown below…
Read moreDefinition: The frequency is the number of oscillation per unit time. It is used for defining the cyclic process like rotation, oscillation, wave etc. The completion of the cyclic process at particular interval of time is known as the frequency. The SI unit of the frequency is Hertz. The symbol λ represents it. The one…
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