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Showing posts from November, 2022

What is Oil Circuit Breaker?

What is Oil Circuit Breaker?  Basically an oil circuit breaker is a type of high-voltage circuit breaker. When oil is used to extinguish the arc, it is known as an oil circuit breaker. In this type of circuit breaker, oil is used, but mineral oil is preferable. It performs better in insulating properties than air. The rotating contact and the fixed contact are immersed in insulating oil. When the arc forms, the oil vaporizes and decomposes into hydrogen gas. It eventually forms a hydrogen bubble around the bracket. This highly compressed gas bubble prevents the arc from striking again after the current reaches the zero crossing of the arc cycle.

What is SF6 Circuit Breaker?

What is SF6 Circuit Breaker?  SF6 circuit breaker is basically known as sulfur hexafluoride circuit breaker and is a type of medium voltage circuit breaker. When sulfur hexafluoride gas is used to extinguish the arc, it is known as SF6 circuit breaker. This gas is known to extinguish the arc rapidly, as it has a very high dielectric strength and acts as an insulating medium. A large amount of arcing occurs when the fixed and moving contacts move away from each other during a trip or off condition. In SF6 circuit breakers, since the gas enclosure is arcing, the dielectric strength of the gas increases during arc formation. This automatically reduces or cancels the high current generated. SF6 circuit breakers have excellent insulating properties and high electro-negativity. It is used at voltages from 33KV to 800KV.

What is VCB?

What is VCB?  VCB is known as vacuum circuit breaker. And vacuum circuit breaker is a type of medium voltage circuit breaker. Circuit breakers are all about extinguishing high-tripping currents or arcs generated in power-off conditions. So, when vacuum is used to extinguish the arc, it is known as vacuum circuit breaker. VCB is used at voltage of 11KV to 33KV. A large amount of arcing occurs when the stationary and moving contacts move away from each other during a trip or off condition. In this circuit breaker, since arcing occurs in a vacuum enclosure, the dielectric strength of the vacuum increases during arcing. In this circuit breaker, since arcing occurs in a vacuum enclosure, the dielectric strength of the vacuum increases during arcing. This automatically reduces or cancels the high current generated. It has a dielectric recovery character, excellent interruption and can interrupt the high-frequency current caused by arc instability, which is superimposed on the line frequency

What is MPCB?

What is MPCB?  MPCB ​​is known as motor protection circuit breaker and is a type of low-voltage circuit breaker. MPCB ​​works similar to MCCB, but the electrical features are designed in such a way that it efficiently protects the motors from various types of faults. Also, it has an on-off switch to switch the power supply to the motor on or off. It is worth noting that MCCB can also be used to protect motors, but it has limited motor protection functions as compared to MPCB. Some other faults that MPCB can protect the motor from are phase loss, current imbalance and under-voltage fault. MPCB ​​has a special feature of auto-resetting. This allows the motor to resume its function after a certain period of time after the motor is tripped. MPCB ​​has an adjustable bimetallic strip for overload protection. And this strip can be adjusted to any two set values ​​for overload protection. MPCB ​​can also provide protection against line-to-line faults and line-to-ground faults.

What is RCBO?

What is RCBO?  An RCBO is known as a residual current circuit breaker with overcurrent. And this is a type of low-voltage circuit breaker. Basically it is used to protect against earth leakage fault current along with over current. RCBO has additional protection against overload and over current. RCBO is mainly used in microcontrollers and can also be called as a combination of MCCB and RCCB. It is more useful than RRCB, as RCCB does not provide protection against over current. Some RCBOs also have indicators to indicate any earth fault.

What is RCCB?

What is RCCB?  RCCB is a residual current circuit breaker. And this is a type of low-voltage circuit breaker. Basically RCCB is used to protect against earth leakage fault current. It has small current ratings, typically up to 160A. RCCB provides protection against electric shock. This is because the role of RCCB is primarily to detect earth leakage and trip the circuit if detected. And basically there is a test circuit operation to check if the RCCB is working or not.

What is MCCB?

What is MCCB? MCCB is known as molded case circuit breaker. And this is a type of low-voltage circuit breaker. MCCB is generally used for high power requirement areas like industrial or large commercial applications. Also it can be used up to 2500 A. This enables the MCCB to be used in larger applications. MCCB's interrupt rating can go up to 200000 A. MCCB has various tripping functions like continuous ampere, long time delay, short time pickup, short time delay, instantaneous pickup and ground fault pickup. These are adjustable trip functions, meaning you can set the trip parameters to suit your needs; Thus providing more flexibility to the user to design the circuit. The MCCB is enclosed in a molding or housing of molded material and hence is known as a molded case circuit breaker.

What is MCB?

What is MCB?  MCB is known as miniature circuit breaker. And this is a type of low-voltage circuit breaker. MCBs are used for household purposes or for low power requirements such as small electrical panels. Also it can be used up to 100 A only. And its interrupt rating is up to 18000 A. MCBs are very popular due to their ability to trip quickly.

What is a Circuit Breaker?

What is a Circuit Breaker?   Basically, circuit breakers are an essential part of an electrical circuit. Circuit breakers are devices used as protective switches to pass current with tripping conditions. When it detects a trip condition, the circuit breaker opens its contact and isolates the input and output voltages from contacting each other. And the basic function of circuit breakers is to interrupt the current after a fault is detected. It remains open until the user resets the trip. Common Types of Industrial Circuit Breakers is a MCB (Mini Circuit Breaker)  MCCB (Molded Case Circuit Breaker)  RCCB (Residual Current Circuit Breaker)  RCBO (Residual Current Circuit Breaker with Overcurrent)  MPCB ​​(Motor Protection Circuit Breaker)  VCB (Vacuum Circuit Breaker)  SF6 (Sulfur Hexafluoride Circuit Breaker) Oil circuit breaker

X-Ray Spectrometers Multiple Choice Questions and Answers

X-Ray Spectrometers Multiple Choice Questions and Answers 1. The crystal used as X-ray grating has _______ dimensional lattice arrays. a) One b) Two c) Three d) Four Answer: Three. 2. X-ray diffractometers provide ____________ information about the compounds present in a solid sample. a) Quantitative b) Qualitative c) Quantitative and qualitative d) Either quantitative or qualitative Answer: Quantitative and qualitative 3. X-ray emission must be analysed against a background of _______ radiation. a) Blue b) Yellow c) White d) Green Answer: White. 4. In Diffractometer, the identification of a component of the sample from its powder diffraction pattern is based upon the _________ of lines and their relative ___________ a) Number, length b) Number, intensity c) Position, length d) Position, intensity Answer: Position, intensity. 5. In Diffractometers, line intensities depend on ______ and kind of atomic reflection centres in each set of plates. a) Number b) Position c) Length d) Distance

Radiochemical Techniques Multiple Choice Questions and Answers

Radiochemical Techniques Multiple Choice Questions and Answers 1. The difference between the pulses having amplitudes between the two triggering levels is called __________ a) Pulse width b) Energy gap c) Window width d) Amplitude variation Answer: Window width. 2. A quench curve can be constructed by plotting the counting efficiency versus ____________ a) Q-number b) Quench factor c) H-number d) Disintegrations Answer: H-number. 3. The reduction in counting efficiency of the scintillation detector is called as __________ a) Disintegration b) Decay c) Quenching d) Reduction Answer: Quenching. 4. In liquid scintillation counter, which of the following is a fluorescent substance? a) Solvent b) Solute c) Crystal d) Reagent Answer: Solute. 5. Due to the presence of red, green and yellow colour in the vial, which of the following occurs? a) Chemical quench b) Interference quench c) Colour quenching d) Self-absorption Answer: Colour quenching. 6. When UV light is absorbed by the fluor molecu

Dissolved Component Analysers Multiple Choice Questions and Answers

Dissolved Component Analysers Multiple Choice Questions and Answers 1. If the differential amplifier gives a positive output then it infers which of the following (Reference output is given to the positive terminal and sample output is given to the negative terminal)? a) The concentration of silica in sample and reference solution is equal b) The concentration of silica in a reference solution is more than that in the sample solution c) The concentration of silica in sample solution is more than that in the reference solution d) Further processing is required to come to any conclusion Answer: The concentration of silica in sample solution is more than that in the reference solution. 2. Which of the following are used to free bound ions or liberate bound ions? a) Colouring agents b) Ammonia Buffer c) Reagents d) Iodine solution Answer: Reagents. 3. Which of the following are added for pH adjustment in sodium analyser? a) Acidic solution b) Basic solution c) Hydrazine d) Ammonia buffer A

Ion Analysers Ion Analysers Multiple Choice Questions And Answers

Ion Analysers Multiple Choice Questions And Answers 1. The dilution of solution must not reduce the level of ammonia below _________ a) 10-2 M b) 10-5 M c) 10-8 M d) 10-9 M Answer: 10-5 M. 2. When electrode potential response is plotted as a function of ammonia concentration on a semi-log graph, the graph obtained will be ____________ a) A straight line b) Parabolic c) Sigmoidal d) A curve Answer: A straight line. 3. If a solid or liquid membrane is placed in pure water, the membrane dissolves slightly, producing an equilibrium concentration of the measured ion. This is represented as __________ a) A constant, Eo b) Activity c) Blank correction, Cb d) Concentration of standard solution, Cs Answer: Blank correction, Cb. 4. In liquid membrane electrode, the liquid ion exchanger is held in a porous disc of _____________ a) Solid material b) Semi-permeable membrane c) Hydrophobic material d) Water absorbing material Answer: Hydrophobic material. 5. Ion selective electrodes have ________ li

PH Meters Multiple Choice Questions and Answers

PH Meters Multiple Choice Questions and Answers 1. In Hydrogen electrode, the electrode is placed in a solution of ____ M Hcl. Fill in the blank. a) 0.5 b) 1 c) 2 d) 3 Answer: 1. 2. Which of the following is the value of hydrogen ion concentration of pure water? a) 1×10^7 moles/litre b) 1×10^5 moles/litre c) 1×10^6 moles/litre d) 1×10^8 moles/litre Answer: 1×10^7 moles/litre. 3. Which of the following is the relation between hydrogen and hydroxyl ion concentration of pure water? a) Value of hydrogen ion concentration is greater b) Value of hydroxyl ion concentration is greater c) They are both always the same d) The concentrations keep changing Answer: They are both always the same. 4. Which of the following is not a failure in pH meters? a) Defective electrodes b) Defective input circuitry c) Defective electronic circuitry d) Defective calibration Answer: Defective calibration. 5. The electrodes used in pH measurement have which of the following internal resistances? a) Very low resis

Pollution Monitoring Instruments Pollution Monitoring Instruments Multiple Choice Questions and Answers

Pollution Monitoring Instruments Multiple Choice Questions and Answers 1. Non-dispersive infrared analyzer depends on the characteristic absorption of the CO molecule at a wavelength of __________ a) 5.4 µm b) 4.6 µm c) 8.9 µm d) 10.8 µm Answer: 4.6 µm. 2. In the conductivitimetric method, to measure the conductivity of the cell, 5V ___________ is applied across the electrodes. a) DC b) AC c) Pulsating DC d) DC or AC Answer: AC. 3. Sensitivity to total sulphur by Flame-photometric detector is which of the following levels? a) 0.1 ppm b) 1 ppm c) 2 ppm d) 0.01 ppm Answer: 0.01 ppm. 4. In West-Gaeke colourimetric procedure, the intensity of the red purple colour is measured photometically and it is proportional to the concentration of sulphur dioxide. What is the red purple coloured compound? a) Sodium tetra chloromercurate b) Dicholorosulphitomercurate complex c) Ammonia molybdate d) Paraosaniline sulphonic acid Answer: Paraosaniline sulphonic acid. 5. Which of the following are not the

Industrial Gas Analysers Multiple Choice Questions and Answers

Industrial Gas Analysers Multiple Choice Questions and Answers 1. In polarographic cell when potential is applied, oxygen is reduced at __________ when KCl is present. a) Anode b) Cathode c) Electrolyte d) Both the electrode Answer: Cathode. 2. A pink coloured dye complex is formed when air containing NO2 is passed in an absorbing solution consisting of __________ and diamine dissolved in the acetic acid medium. a) Sulphuric acid b) Sulphonyl c) Sulphonic acid d) Sulphanilic acid Answer: Sulphanilic acid. 3. Which of the following is true about the two charged vanes that produce electric field in Paramagnetic oxygen analyzer? a) Both the vanes should be at higher potential than the test body b) Both the vanes should have the same potential as the test body c) One vane should be at higher potential than the test body and the other vane should be at lower potential d) Both the vanes should be at lower potential than the test body Answer: One vane should be at higher pot