Description : An electric furnace producing heat by means of an electric arc struck between each of three electrodes and the charge is called __________ furnace. (A) Resistance (B) Arc (C) Low frequency induction (D) None of these
Last Answer : (B) Arc
Description : The electric furnace in which heat is produced by a combination of induced current and skin effect is called __________ furnace. (A) Arc (B) Resistance (C) Low frequency induction (D) High frequency induction
Last Answer : (D) High frequency induction
Description : __________ furnace is generally used in the non-ferrous foundries. (A) Direct arc (B) Indirect arc (C) Resistance (D) Induction
Last Answer : (B) Indirect arc
Description : The resistance furnace produces heat by the (A) Electric arc struck between electrodes and the charge (B) Flow of current through a heating element (C) Combination of induced current and skin effect (D) None of these
Last Answer : (B) Flow of current through a heating element
Description : The usual energy consumption in electric arc furnace steel making is __________ KWh/ton of steel. (A) 60 - 100 (B) 400 - 700 (C) 1200 -1500 (D) 2000 - 2300
Last Answer : (B) 400 - 700
Description : Out of the following methods of heating the one which is independent of supply frequency is (A) electric arc heating (B) induction heating (C) electric resistance heating (D) dielectric heating
Last Answer : (C) electric resistance heating
Description : Power-factor of industrial arc and induction furnace is:
Last Answer : Power-factor of industrial arc and induction furnace is: very low lagging
Description : The refractory lining of the bottom in a basic electric arc furnace is made of (A) Silica (B) Alumina (C) Magnesia (D) Fireclay
Last Answer : Option C
Description : State any two applications of each for the following types of electrical heating : (i) Direct resistance heating(ii) Indirect induction heating (iii) Direct.arc heating (iv) Dielectric heating
Last Answer : (i) Direct resistance heating:- 1. This type of heating used for industrial purpose 2. Salt bath heating: This utilized for the purpose of carbonizing, tempering, quenching and hardening of steel tools 3. ... purpose. 14)In foundry for heating of sand, core, which are used in molding processes.
Description : In low or standard frequency induction furnace, heat is produced by the (A) Combination of induced current and skin effect (B) Induction and resistance (C) Current flow through a heating element (D) None of these
Last Answer : (B) Induction and resistance
Description : Thermit welding is categorised as the __________ welding. (A) Forge (B) Fusion (C) Resistance (D) Arc
Last Answer : (B) Fusion
Description : Consumable electrodes are used in the __________ welding. (A) Gas (B) Arc (C) Thermit (D) Resistance
Description : Projection welding & stud welding is categorised as the __________ welding. (A) Pressure (B) Thermit (C) Resistance (D) Arc
Last Answer : C) Resistance
Description : Which type of welding is generally used in automobile sector? a) Electric arc welding b) Electric resistance welding c) Gas welding d) Forge welding
Last Answer : b) Electric resistance welding
Description : Identify the correct combination of respective Electric arc welding and Electric resistance welding methods : (A) Butt welding and Seam welding (B) Hydrogen shielding and Projection welding (C) Seam welding and Coated electrode welding (D) Coated electrode welding and Hydrogen shielding
Last Answer : Identify the correct combination of respective Electric arc welding and Electric resistance welding methods : (A) Butt welding and Seam welding (B) Hydrogen shielding and Projection welding ... Seam welding and Coated electrode welding (D) Coated electrode welding and Hydrogen shielding
Description : Pot furnace which is either regenerative or recuperative, is used in the manufacture of (A) Glass (B) Stainless steel (C) Potteries (D) Refractory bricks
Last Answer : (A) Glass
Description : A current `i` ampere flows in a circular arc of wire whose radius is `R`, which subtend an angle `3pi//2` radian at its centre. The magnetic induction
Last Answer : A current `i` ampere flows in a circular arc of wire whose radius is `R`, which subtend an angle `3pi//2` radian at ... 0)i)/(R )` D. `3mu_(0)i)/(8R)`
Description : Nitriding of steel is done (in electric furnace) at __________ °C. (A) 510 (B) 1720 (C) 2210 (D) 910
Last Answer : (A) 510
Description : While the fuel fired furnace can be used upto a maximum temperature of about 1700°C, the electric furnace can be used upto a temperature of about __________ °C. (A) 2000 (B) 3000 (C) 4500 (D) 6000
Last Answer : (C) 4500
Description : Fusion zone in the electric furnace used for reduction of phosphate rock to elemental phosphorous is maintained at __________ °C. (A) 250-300 (B) 500-750 (C) 950-1050 (D) 1400-1450
Last Answer : (D) 1400-1450
Description : A mixture of phosphate rock __________ is heated in an electric furnace to produce phosphorous. (A) Salt & coke (B) Sand & coke (C) And coke (D) And sand
Last Answer : (B) Sand & coke
Description : Electric furnace method for production of phosphorous uses phosphate rock and __________ (A) Phosphoric acid (B) Coke (C) Sulphuric acid (D) Silica and coke
Last Answer : (D) Silica and coke
Description : The amount of combustible escaping unconsumed from the furnace, depends upon the (A) Air supplied and furnace temperature (B) Burner design (thoroughness of mixing versus stratification) (C) Air preheat and the flow of ... , by acceleration or by change of direction) (D) All (A), (B) and (C)
Last Answer : (D) All (A), (B) and (C)
Description : Nitric acid is produced on commercial scale in a fertiliser plant by (A) Oxidation of ammonia (B) CaNO3 + H2SO4 reaction (C) Passing air through high voltage electric arc (D) None of these
Last Answer : (A) Oxidation of ammonia
Description : Why can't we use aluminium or copper under the induction cook pot?
Last Answer : The most suitable material to use under induction cook pot is iron.We cannot use aluminum or copper because: 1.)Induction cook pot works through electromagnetic induction to produce heat.Neither aluminum ... of heavy currents unlike when you're using iron this making the whole process very costy.
Description : In a 100 TPD Sponge Iron plant, the sponge iron is fed to the Induction melting furnace, producing molten steel at 88% yield. The Energy consumption details are as follows: Coal Consumption : 130 ... molten steel (product). 3. Total Energy Consumption of Plant in Tons of Oil Equivalent (TOE )
Last Answer : a) Specific Energy Consumption of Induction Melting Furnace Molten Steel Production from the Induction melting furnace per day = 100 x 88/100 = 88 TPD Total Energy Consumption of the Plant = 82400 kWh ... mark c) Total Energy consumption of Plant in ToE = 655864000/107 = 65.586 ToE
Description : In the heating process of the ________type a simple method of temperature control is possible by means of a special alloy which loses its magnetic properties at a particular high temperature and regains ... ) core type induction furnace (C) coreless induction furnace (D) high frequency eddy current
Last Answer : Ans: D Magnetic property of alloy changes with change of the temperature and Heat is produced due to eddy current = i2R and i α f2
Description : Differentiate between core type and core less induction furnace.
Last Answer : Sr.No. Core type induction furnace. Core less induction furnace. 1 Less leakage flux More leakage flux 2 Power factor is good Power factor is poor 3 ... normal frequency is used. Due to high frequency, high voltage supply, time required for heating is less.
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 : The speed of a squirrel-cage, multi-speed, induction motor, as used aboard ship, is varied by changing the __________. A. number of connected poles in the stator B. frequency to the motor C. excitation voltage D. resistance of the rotor circuit
Last Answer : Answer: A
Description : The variable resistance placed in the rotor circuit of a wound-rotor induction motor provides for __________. A. speed control B. frequency control C. voltage control D. use as a split-phase motor
Description : Projection welding is (i) Electric arc welding (ii) Gas welding (iii)Spot welding (iv) None
Last Answer : (iv) None
Description : Among gas and electric arc welding, which has the higher rate of heating? a) Gas welding b) Electric arc welding c) Gas welding and electric arc welding have equal rate of heating d) Cannot be determined
Last Answer : b) Electric arc welding
Description : Rails in the field are generally welded by using a) Thermit welding b) Gas welding c) Electric arc welding d) Forge welding
Last Answer : a) Thermit welding
Description : The electric arc welding is a type of ............. welding. (a) forge (b) fusion
Last Answer : b) fusion
Description : Two parallel wires carrying currents in opposite directions will: w) attract each other x) repel each other y) cause an electric arc to form z) not affect each other
Last Answer : ANSWER: X -- REPEL EACH OTHER
Description : Arc welding uses following electric supply (A) ac (B) dc (C) both ac and dc (D) spiral waveform
Last Answer : both ac and dc
Description : In the illustration, the purpose of part B is to _________. EL-0033 A. increase resistance in series with the contacts as they close to prevent arcing B. create a magnetic field in the steel ... event of an overload D. provide ventilation to the contact when the breaker is close to rated capacity
Last Answer : Answer: B
Description : Arc in a circuit behaves as (a) a capackive reactance (b) an inductive reactance (c) a resistance increasing with voltage rise across the arc (d) a resistance decreasing with voltage rise across the arc
Last Answer : (d) a resistance decreasing with voltage rise across the arc
Description : Compare resistance welding and arc welding.
Last Answer : Sr. No Resistance Welding Arc Welding 1 It is plastic welding It is fusion welding. 2 Arc is produced by heat due to resistance of flow of current by work and by application ... 8 Less skilled operator can do the job. More skilled operator is required to the job
Description : Compare between Resistance welding and Arc welding on any six points.
Last Answer : Sr.No Parameters Resistance Welding Arc Welding 1 Type of welding Plastic/Pressure/Non-fusion welding Fusion/Non pressure welding 2 Principle of heat developed Heat ... It is suitable for mass production It is suitable for heavy job, maintenance and repair work
Description : The operation of the relay which is most affected due to arc resistance is A) Mho relay B) Reactance relay C) Impedance relay D) All are equally affected
Last Answer : The operation of the relay which is most affected due to arc resistance is Mho relay
Description : Arc resistance (1) increases with increase in arc current (2) decrease with increase in arc current (3) is independent of arc current (4) is independent of arc length
Last Answer : Arc resistance decrease with increase in arc current
Description : In the manufacture of H3 PO4 (ortho); strong H2 SO4 leaching wet process as compared to electric furnace process (A) Uses lower grade phosphate rock (B) Requires lower capital investment in the plant (C) Produces lower purity acid (D) Is very costly
Last Answer : (C) Produces lower purity acid
Description : Heating a mixture of phosphate rock, coke and sand in an electric furnace produces (A) Phosphoric acid (B) Ammonium phosphate (C) Phosphorous (D) Superphosphate
Last Answer : (C) Phosphorous
Description : Electrolytic reduction cell used for conversion of calcined Al2O3to Al is a carbon lined furnace operating at 800-900 °C. The purpose of electric current supplied to the furnace is to (A) Achieve very high ... by the generation of heat (C) Electrolytically dissociate alumina (D) Both (B) & (C)
Last Answer : (D) Both (B) & (C)
Description : Test specimen for determination of refractoriness under load (RUL) of a refractory is heated in a (A) Furnace employing neutral atmosphere (B) Carbon resistance furnace (C) Reducing atmosphere (D) Furnace employing negative pressure
Last Answer : (B) Carbon resistance furnace
Description : Increase in ash content of blast furnace coke (A) Reduces its consumption in the furnace (B) Increases its consumption in the furnace (C) Does not affect its consumption in the furnace (D) Decreases its hardness and abrasion resistance
Last Answer : (B) Increases its consumption in the furnace
Description : High ash containing coke (A) Produces more slag when used in the blast furnace (B) Has poor strength and abrasion resistance (C) Is desirable in producer gas manufacture (D) None of these
Last Answer : (A) Produces more slag when used in the blast furnace
Description : How long will the average cordless kettle last Is it the same as an electric coffee pot?
Last Answer : Cordless kettles will last a long time, especially if you're able to buy a stainless steel model. Cordless electric kettles are generally more durable than an electric coffee pot.