Describe the construction of high pressure mercury vapour lamp with neat sketch

1 Answer

Answer :

image

Construction:-  It consists of an inner bulb generally of silicon, to withstand high temperatures. The bulb contains a small quantity of mercury and argon. It is protected by outer glass, this may be cylindrical or elliptical. The space between the two bulbs is filled with nitrogen at a pressure of half atmosphere. The discharge tube has three electrodes, namely two main electrodes A and B and one starting electrode. The starting electrodes are connected through a resistance of about 10-30 k ohm to the main electrode, located at the far end. The electrodes are of tungsten wire helices filled with electron emissive materials, usually barium and strontium carbonates mixed with thorium.


OR


The construction & connection diagram is as shown in figure. As per this construction there are following components. 

Choke: The choke is acting as the ballast. At the time of supply voltage variation of current flowing through the inner tube is maintained constant to keep uniform light intensity. Sometimes choke can be designed for to get the higher voltages & to apply the inner tube of mercury vapour lamp. Starting resistance/limiting resistance: Whenever current flows through the starting resistance there is a I2R loss which is converted into heat. If the temperature of this heat goes near about 6000C then there will be heating effect & inert gases ionization will be start. Auxiliary electrode & Main electrode: It is made by high resistive element. The ionization is taking place through the inert gases whenever current flows from auxiliary electrode to main electrode. Inner Tube: The various inert gases e.g. Argon, Nitrogen etc with mercury powder are filled in the inner tube at low pressure or high pressure. Outer Tube: The function of outer tube is to make the vacuum surrounding the inner tube to avoid thermal dissipation or to maintain 6000C surrounding the inner tube. Power factor improvement Capacitor: The function of power factor improvement capacitor is to improve the power factor 0.5 to 0.95

Related questions

Description : Explain with neat circuit diagram, low pressure mercury vapour lamp.

Last Answer : Diagram of low pressure mercury vapour lamp:  Working:-  Whenever 1-ph, 230V, AC Supply is provided to the discharge tube of MVL initially to current will flow from Phase to the ... Capacitor: The function of power factor improvement capacitor is to improve the power factor 0.5 to 0.95 

Description : Describe with neat sketch operation of seam type resistance welding.

Last Answer : 1) Seam Welding its neat labelled sketch:  Explanation: Seam welding is nothing but series of continuous spot welding Working: Job is kept in between two electrodes under ... reached supply is cut down and external pressure is applied simultaneously across the job to complete weld.  

Description : Explain with neat diagram construction and working of Ajax Wyatt vertical core induction furnace.

Last Answer : Neat sketch of Ajax Wyatt' vertical core furnace: Construction of Ajax Wyatt' vertical core furnace: Vertical core type induction heating furnace is nothing but transformer. It consists of ... is utilized to melt the charge. Where, R = Resistance of charge & I secondary current.

Description : What is the difference between a sodium vapour lamp, Which gives out a yellowish colour illumination, and a mercury vapour lamp that gives out a white colour illumination?

Last Answer : Answer I: The light in Sodium Vapour lamp is from an atomic emission process whereas in Mercury Vapour Lamp it is, finally, from fluorescence emission. The mechanism of light emission in a sodium ... from a fluorescent lamp is moderate (60 lumens/watt) while the color-rendering index is high.

Description : Describe with neat sketch the construction and working of surface condenser

Last Answer : Construction- It consists of horizontal cast iron cylindrical vessel pack with tubes, through which the cooling water flows. The ends of the condenser are cut off by vertical perforated type plates into ... ; the secondary function of condenser is to supply pure and hot feed water to boiler.  

Description : Describe with neat sketch construction details of clutch plate.

Last Answer : Fig:- Single Plate Clutch Constructional details : It consist of steel plate with a splined central hub. Annular friction facing are attached to the steel plates by rivets. Special resins are ... are similar type of slots in each of the two plates situated on either side of the hub flang 

Description : Describe the construction and working of D-MPFI and L-MPFI with help of neat sketch.

Last Answer : D-LMFI System: It is Manifold fuel injection system.In this type, the vacuum in the intake manifold and volume of air by its density are sensed in this type of MPFI system .As air enters into ... intake manifold , the air flow sensor measures the amount of air and sends information to ECU.

Description : Describe in brief with neat sketch construction of tunnel with needle beam method

Last Answer : In this method stout timber beam known as needle beam is used which forms the main temporary support during the excavation. Construction steps: (a) First of all a small drift of about 1 1 m is ... . (d) After excavation, the lining is provided to the tunnel section and mucking is done. 

Description : Describe with neat sketch the construction and working principle of MOSFET.

Last Answer : Construction and working principle of MOSFET:  A) Depletion type MOSFET: Construction: The N-channel depletion type MOSFET is formed on P-type silicon substrate with two heavily ... accumulation of electrons and hence more current. Thus the MOSFET is a gate voltage controlled device.

Description : Explain with neat sketch Phreatic line in earthen dam with pressure head at different point and show construction points of this line. 

Last Answer : Procedure for locating the Phreatic line i) Draw an earthen dam having upstream face AB with water surface. ii) On water surface measure distance BC = 0.3 L C is starting pt of base parabola. Let F' ... parabola i.e. Phreatic line. viii) Here G,Q1,Q2,Q3,Q4 and B represent Phreatic line 

Description : Write the procedure of construction of WBM road with neat sketch showing various components

Last Answer : Construction Procedure:  a) Preparation of Foundation: The foundation for receiving the layer of WBM may be either the sub-grade or sub-base or base course. The depressions and pot holes on the existing road ... water and rolled. No traffic is allowed till WBM layer sets and dries out. 

Description : Illustrate with neat sketch the construction of fuel injector

Last Answer : Diesel Fuel Injector: The injector assembly consists of - i) a needle valve ii) a compression spring iii) a nozzle iv) an injector body. When the fuel is supplied to lift the injection pump it ... and hence the valve opening pressure is controlled by adjusting the screw provided at the top.  

Description : Explain with neat sketch construction of PIN Diode. Draw its characteristics in reverse bias mode. 

Last Answer : Construction A PIN diode is made up of three semiconductor materials; two heavily doped P- and N- type material separated by an intrinsic (undoped) semiconductor (I) as shown in above figure ... . This advantage allows the PIN diode to process even weak signals.  Characteristics

Description : Explain construction and working of Combination Die with neat sketch.

Last Answer : Combination Die: In this both cutting and non-cutting operations are performed at one station of the press in every stroke of the ram. Figure shows a combination of blanking and drawing die.In this ... as blank holder when the drawing punch descends and draws the blank into the desired shape.

Description : Explain in detail principle, construction and working of Radiation Pyrometer with neat sketch.

Last Answer : Radiation pyrometer Principle: According to Stefan Boltzmann's law, the intensity of radiant energy emitted by a hot target varies as the fourth power of its absolute temperature. ... is calibrated in terms of target temperature by using either a voltmeter or Wheatstone bridge circuit.

Description : Explain construction and working of Bimetallic Thermometer with neat sketch.

Last Answer : Bimetallic thermometer: Diagram Construction and working: Bimetallic strip consists of two strips of metal such as invar and brass welded together, each strip made from a metal having a ... The movement of the bimetallic strip is utilized to deflect a pointer over a calibrated scale. 

Description : Explain Construction and working of Francis Turbine with neat sketch.

Last Answer : The main parts of the Francis turbine are: 1) Penstock: It is the large pipe which conveys water from the upstream of the reservoir to the turbine runner. 2) Spiral casing: It is a closed passage ... After doing the work the water is discharge to the trail race through the draft tubes.

Description : Explain the construction and working of induced draft cooling tower with neat sketch.

Last Answer : Induced draft cooling tower :  Diagram: Construction and working: Cooling towers are employed to cool utility cooling water by direct contact with air. The parts of a cooling tower are ... top pulls the hot air through the fills and cooled water gets collected in the cold water basin.

Description : With neat sketch explain the construction and working of heat exchanger used for handling corrosive liquid.

Last Answer : Graphite block heat exchanger:   Graphite heat exchangers are well suited for handling corrosive fluids. Graphite is inert towards most corrosive fluids and has very high thermal conductivity. Graphite being ... vertical faces direct the service fluid through the exchanger in a cross flow.

Description : Explain the construction of ‘Disc Brake’ with neat sketch.

Last Answer : Construction of Disc Brake: Modern vehicles always equipped with disc brakes on at least the front two wheels. It consists of mainly 3 parts, [1] Rotor [2] Caliper [3] Brake pads In ... drum. Friction surface directly exposed to air cooling which results better (faster) heat dissipation. 

Description : Explain with neat sketch the construction and working principle of megger.

Last Answer : Megger: Construction of Megger : Two coils: the current coil and pressure coil are mounted at an angle on the same spindle and form the part of the moving system. These coils are ... force produces a torque that is used to deflect the pointer of the device which gives some reading.

Description : Explain with neat sketch; the construction and working principle of Repulsion type moving iron instrument.

Last Answer : Repulsion Type Moving Iron Instrument: Construction: It consist of fixed cylinder hollow coil which carries operating current inside the coil there are two soft iron pieces. One of which is ... magnetized with same polarity a repulsive force act on them and moving iron piece gets deflected. 

Description : Give construction working principle of RTD with a neat sketch.

Last Answer : Diagram Working: An RTD (resistance temperature detector) is a temperature sensor that operates on the measurement principle that a material's electrical resistance changes with temperature. ... change m resistance of the RTD, which is then used to calculate change in temperature.

Description : State with neat sketch the construction of three phase autotransformer.

Last Answer : Operation: Working principle is based on self-induction. When three-phase ac supply is given to star connected three windings, flux is produced and gets linked with each phase winding. The emf ... . Depending upon the position of variable terminal, we get variable AC voltage at the output.

Description : Draw a neat labelled block diagram of AC electric locomotive. State the function of each part.

Last Answer : labelled diagram ofAC electric locomotive:  Function of AC electric locomotive Parts: 1) Overhead contact wire: Supply of 1-ph, 25KV, 50Hz, AC is given to overhead conductor. 2) Current collecting ... mechanical power to run the train i.e. DC series motor which is used as traction motor.

Description : In a barometer, mercury is preferred over water because (a) mercury is a good conductor of heat (b) mercury is shining and therefore its level can be read easily (c) mercury is available in pure form (d) mercury has high density and low vapour pressure

Last Answer : Ans:(d)

Description : Describe with a neat diagram the working of a simple vapour compression refrigeration system. Represent the cycle on P–V and T–S diagram. 

Last Answer : Vapour compression refrigeration cycle: The vapor-compression uses a circulating liquid refrigerant as the medium which absorbs and removes heat from the space to be cooled and subsequently rejects that heat elsewhere. Figure shows ... the compressor. P-V Diagram T-S diagram: 

Description : A common fluorescent tube contains (a) sodium vapour (b) argon at low pressure (c) mercury vapour at low pressure (d) mercuric oxide and neon

Last Answer : Ans:(c)

Description : Mercury is often used in barometer because (A) It is the best liquid (B) The height of barometer will be less (C) Its vapour pressure is so low that it may be neglected (D) Both (B) and (C)

Last Answer : Answer: Option D

Description : Luminance efficiency is minimum for a a. Fluorescent tube b. High wattage light bulb c. Mercury vapor lamp d. Low wattage light bulb

Last Answer : d. Low wattage light bulb

Description : Luminous efficiency is least for a A. mercury vapor lamp B. low-wattage light bulb C. high-wattage light bulb D. fluorescent tube

Last Answer : B. low-wattage light bulb

Description : Luminance efficiency is minimum for a ∙ a. Fluorescent tube ∙ b. High wattage light bulb ∙ c. Mercury vapor lamp ∙ d. Low wattage light bulb

Last Answer : d. Low wattage light bulb

Description : Describe in brief with neat sketch: i) English bond ii) Flemish bond

Last Answer : English bond : The Bond with alternate courses of headers and stretchers with a closer placed next to quoin header is called as the English Bond. Points Should be Remembered for English bond: 1. A ... . 4. Flemish Bond is slightly economical as a number of brick bats can be used.

Description : Describe push rod overhead valve operating mechanism with neat sketch.

Last Answer : Push rod Overhead valve operating mechanism (OHV 4 -S engine): An overhead valve engine (OHV engine) is an engine in which the valves are placed over the cylinder head. The camshaft drive-chain ... . Overhead valve arrangement makes the engine slightly shorter than overhead camshaft.   OR  

Description : Describe mono-shock regular swing arm suspension system with neat sketch.

Last Answer : Mono-shock Regular swing arm : Original technology of mono-shock comes from the racing world where motor cycles compete in most extreme conditions. More advanced version of this technology is employed in these ... only one shock to adjust, and there is no worry about matching two shocks.   

Description : Describe working of constant mesh gear box with neat sketch.

Last Answer : Working of constant mesh gear box: A simplified diagram of constant mesh box has been shown in Figure. In this gear box, all gears on the main transmission shaft are constantly connected to corresponding ... In this way by sliding the second dog clutch, second and first gears are obtained.

Description : Describe constructional details of single cradle frame with neat sketch.

Last Answer : Single cradle frame :  The single cradle is the simplest type of motorcycle frame, and looks similar to the first ever motorcycle frames. It is made from steel tubes that surround the engine with a main ... found in off-road motorcycles.  Figure: Typical motor cycle frame of cradle type

Description : Describe with neat sketch the working of “Air Suspension”

Last Answer : Working: An air compressor takes the atmospheric air through a filter and compresses it to a pressure of about 240 MPa, at which pressure the air in the accumulator tank is maintained, which ... air gets further compressed and absorbs the shock when the wheel encounters a bump on the road. 

Description : Describe working of Stabilizer bar with neat sketch 

Last Answer : Stabilizer (Anti Roll) Bar: Working: When the wheel strikes a bump, it starts vibrating up & down, thus exerting torque on the bar, which acts as a spring. When one road wheel is ... obviate this tendency, a stabilizer is used in car suspension system. It prevents lateral swaying.  

Description : Describe with neat sketch working of air compressor used in automobile workshops. State its two advantages

Last Answer : As shown in ig. Shows two stages reciprocating air compressor with water cooled and intercooler First of all fresh air is sucked from atmosphere in low pressure (L.P) cylinder during its suction ... :  1) Less power is required to drive the compressor.  2) Higher volumetric efficiency 

Description : Describe with neat sketch of working of bomb calorimeter

Last Answer : working of bomb calorimeter:   The calorimeter is made of austenitic steel which provides considerable resistant to corrosion and enables it to withstand high pressure. In the calorimeter use of a strong ... the calorimeter. From the above data the calorific value of the fuel can be found.  

Description : Describe with neat sketch working of full floating type.

Last Answer : Fig:- full floating Rear axle Explanation: The figure shows the full floating axle. The wheel is on the axle casing. Two roller bearings are between the wheel and axle casing. ... supported by the wheel and the axle casing. Fully floating rear axle is used in heavy commercial vehicles 

Description : Describe the working of motorcycle clutch with neat sketch.

Last Answer : Working : While the flywheel is rotating the pressure plates rotate and press against the friction plate. This causes the friction plates and thus the clutch shaft to rotate as well. When the pedal is ... they are not fully pressed by pressure plates. Thus the shaft also stops rotation. 

Description : Describe the working of water/liquid cooling system with neat sketch.

Last Answer : A water-cooled engine block and cylinder head have interconnected coolant channels running through them. At the top of the cylinder head all the channels converge to a single outlet. A pump, driven by a ... speed increases. There is no necessity of maintaining the water up to a correct level.  

Description : Describe the working of four stroke C. I. engine with neat sketch. 

Last Answer : Working principle of CI engine: 1. Suction stroke: During this stroke, inlet valve is open and exhaust valve is closed. Only air is sucked into cylinder during this stroke. The ... burnt gases outside the combustion chamber. Crankshaft rotates by two complete revolutions through 720˚. 

Description : Describe with neat sketch specification of lathe machine.

Last Answer : 1. The height of the centers measured from the lathe bed. 2. The swing diameter over bed. This is the largest diameter of work that will revolve without touching the bed and is twice the height of ... 6. The length of bed. This indicates the approximate floor space occupied by the lathe. 

Description : Describe with neat sketch, the optical square and explain its principle.

Last Answer : Principal of optical square :- the angle between the first incident ray and the last reflected ray is twice the angle between the two mirrors OR If there are two plane mirrors whose reflecting surfaces ... is 450 while that between the first incident ray and last reflected ray is 900 .  

Description : Describe in brief with neat sketch: i) Base line ii) Check line

Last Answer : i) Base line:  Base line is generally the longest line running roughly through the middle of the area. It is laid on a level ground as far as possible. The whole frame work is built upon this line. ... on the opposite side or a line joining some fixed point on any two sides of the triangle. 

Description : With the help of neat sketch, describe block diagram of Electronic Diesel Control Unit (EDC).

Last Answer : EDC: The ECU determines the correct quantity of the fuel to be injected based on the inputs and the data in the look up table. The fuel input depends on the rack position and thus ECU ... ECU can also protect the engine against overheating by regulating the maximum quantity of fuel delivered.

Description : Write neat sketch, describe MPFI system.

Last Answer : MPFI system In the port injection arrangement, the injectoe is placed on the side of the intake manifold near the intake port. The injector sprays gasoline into the air, inside the intake manifold. The ... manifold. If there are six cylinders, there will be six injectors as shown in figure.