Description : Work hardenable alloy steel used to make the bucket wheel excavators, blades of bulldozers and other earth moving equipments contain iron, carbon and (A) Manganese (B) Silicon (C) Nickel (D) Chromium
Last Answer : (A) Manganese
Description : Hard ferrites are used for making (A) Transformer cores. (B) Electrical machinery. (C) High frequency equipment. (D) Light weight permanent magnets.
Last Answer : (D) Light weight permanent magnets.
Description : Manganin is an alloy of (A) copper, manganese and nickel. (B) copper and manganese. (C) manganese and nickel. (D) manganese, aluminium and nickel.
Last Answer : (A) copper, manganese and nickel.
Description : Steel containing low percentage of nickel, chromium & tungsten are termed as the __________ steel. (A) Wrought (B) Tool (C) Alloy (D) Plain carbon
Last Answer : (D) Plain carbon
Description : Bronze is an alloy of (A) Copper and Tin. (B) Copper and Steel. (C) Copper and Mercury. (D) Copper and Aluminium.
Last Answer : (A) Copper and Tin.
Description : Bronze is an alloy of (A) copper. (B) aluminium. (C) silver. (D) carbon.
Last Answer : (A) copper.
Description : Transformer cores are laminated to reduce _____________. A. eddy currents B. secondary flux C. leakage flux D. all of the above
Last Answer : Answer: A
Description : 24 Transformer cores are laminated in order to A. simplify its construction B. minimise eddy current loss C. reduce cost D. reduce hysteresis loss
Last Answer : B. Minimise eddy current loss
Description : Eddy current losses in transformer cores can be reduced by the use of 1. Solid cores 2. Laminated cores 3. Ferrites Select the correct answer using the codes given below : (a) 2 and 3 only (b). 1 and 2 only (c) 1 and 3 only (d) 1, 2 and 3
Last Answer : Eddy current losses in transformer cores can be reduced by the use of 1. Solid cores 2. Laminated cores 3. Ferrites Select the correct answer using the codes given below : (a) 2 and 3 only (b). 1 and 2 only (c) 1 and 3 only (d) 1, 2 and 3
Description : Armature cores in a DC generator are made of laminated steel sheets to _____________. A. fit the curvature of the frame B. increase the hysteresis effect C. reduce eddy current losses D. allow for easy assembly
Last Answer : Answer: C
Description : The percentage of carbon in mild steel is (A) 0.08 to 0.3 % (B) 0.5 to 1.4 % (D) 2.35 % (D) 0.5 %
Last Answer : (A) 0.08 to 0.3 %
Description : Brass is an alloy of (A) copper and zinc. (B) copper and iron. (C) copper and Aluminium. (D) copper and tin.
Last Answer : (A) copper and zinc.
Description : Copper is completely miscible with (A) nickel. (B) gold. (C) hydrogen. (D) lead.
Last Answer : (B) gold.
Description : What is the type of bonding in silicon? (A) Ionic. (B) Covalent. (C) Metallic. (D) Ionic + Metallic
Last Answer : (B) Covalent.
Description : For silicon the forbidden gap is (A) 1.1ev. (B) 0.25ev. (C) 0.5ev. (D) 0.7ev.
Last Answer : (A) 1.1ev.
Description : ________ is an alloy made from iron , chromium and nickel . a) stainless steel b)steel c)brass d)bronze
Last Answer : a) stainless steel
Description : Which of the following alloy steels has the energy saving properties making it suitable for use in electrical machines? (A) Silicon steel (B) Chromium steel (C) Molybdenum steel (D) None of these
Last Answer : (A) Silicon steel
Description : Addition of __________ to steel does not impart hardness. (A) Nickel (B) Copper (C) Chromium (D) Silicon
Last Answer : : Option B
Last Answer : Option B
Description : Nickel and __________ are the alloying element added in steel to increase its toughness. (A) Molybdenum (B) Chromium (C) Vanadium (D) Silicon
Last Answer : Option D
Description : Explain the effect of nickel, chromium, silicon, molybdenum addition on the properties of steel.
Last Answer : 1) Effect of Nickel as alloying Element: i) Provides toughness, corrosion resistance, and deep hardening. ii) Increases resistance to impact iii ) Improves tensile strength 2. Effect ... temper brittleness. iv) increases strength. V0 Mo-carbides help increase creepresistance at elevated temps
Description : The yield strength and tensile strength of low carbon steel may be improved by the addition of (A) Manganese (B) Chromium (C) Nickel (D) Vanadium
Last Answer : Answer: Option D
Description : The yield point phenomenon observed in annealed low carbon steel is due to the presence of the following element. (A) Silicon (B) Carbon (C) Phosphorous (D) Chromium
Description : The dielectric strength of transformer oil should be (A) 100 V. (B) 5 KV. (C) 30 KV. (D) 132 KV.
Last Answer : (C) 30 KV.
Description : Transformer cores are normally made from (A) Soft ferrites (B) High purity iron (C) Grain oriented Fe-Si alloy (D) Al-Ni-Co alloy
Last Answer : (C) Grain oriented Fe-Si alloy
Description : Laminated cores, in electrical machines, are used to reduce?
Last Answer : Laminated cores, in electrical machines, are used to reduce eddy current loss.
Description : Stainless steel is an alloy of - (1) chromium and carbon (2) chromium, carbon and iron (3) chromium and iron (4) carbon and iron
Last Answer : (2) chromium, carbon and iron Explanation: Steel is an alloy made by combining iron and other elements, the most common of these being carbon. When carbon is used, its content in the steel ... 11% chromium content by mass. Stainless steel differs from carbon steel by the amount of chromium present.
Description : Stainless steel is an alloy of (1) chromium and carbon (2) chromium, carbon and iron (3) chromium and iron (4) carbon and iron
Last Answer : chromium, carbon and iron
Description : Which of the following are alloying materials used the manufacture of stainless steel? w) Limestone and carbon x) Calcium oxide and oxygen y) Oxygen and sulfur dioxide z) Chromium and nickel
Last Answer : ANSWER: Z -- CHROMIUM AND NICKEL
Description : The most malleable, ductile low resistivity material is (A) Copper. (B) Aluminium. (C) Silver. (D) Iron.
Last Answer : (C) Silver.
Description : A ferrite core has less eddy current loss than an iron core because ferrites have (A) High resistance. (B) Low resistance. (C) Low permeability. (D) High hysteresis.
Last Answer : (A) High resistance.
Description : Gold and silver are (A) dielectric materials (B) low resistivity conducting materials. (C) magnetic materials. (D) insulating materials.
Last Answer : (B) low resistivity conducting materials.
Description : A fuse wire is made of: (1) an alloy of tin and copper (2) an alloy of tin and lead (3) an alloy of tin and aluminium (4) an alloy of nickel and chromium
Last Answer : (2) an alloy of tin and lead Explanation: Electric fuse wire is an alloy made of tin (63 % lead 37 %. The cross sectional area determines the melting point at a certain current. Alloys (e.g. ... resulting combination of good conductivity (due to the tin) with a low melting point due to the lead).
Description : Which of the following is not an alloy of nickel and chromium? (A) Inconel (B) Hastelloy (C) Nimonic alloys (D) Duralumin
Last Answer : (D) Duralumin
Description : Invar used in thermocouples is an alloy of nickel and (A) Iron (B) Copper (C) Chromium (D) Lead
Last Answer : (A) Iron
Description : Chromel (Nichrome) is an alloy of (A) Chromium and molybdenum (B) Nickel and chromium (C) Molybdenum and nickel (D) Chromium and aluminium
Last Answer : (B) Nickel and chromium
Description : Zircaloy used as a fuel cladding material in a nuclear reactor (thermal) is an alloy of zirconium (A) Tin, nickel, iron and chromium (B) And graphite
Last Answer : (A) Tin, nickel, iron and chromium
Description : Inconel is an alloy of (A) Tin, zinc and nicke (B) Iron, nickel and chromium (C) Copper and nickel (D) Copper and tin
Last Answer : (B) Iron, nickel and chromium
Last Answer : an alloy of tin and lead
Description : An alloy of Iron - Chromium and Nickel makes what
Last Answer : Stainless Steel
Description : Which of the following has a very high carbide forming tendency in steels? (A) Silicon (B) Chromium (C) Nickel (D) Vanadium
Last Answer : (D) Vanadium
Description : Explain the effects of following chemical elements on iron. 1) Chromium 2) Nickel 3) Silicon.
Last Answer : Effect on Iron: 1) chromium: Cr increases the hardenability of steel while there is a minimal effect on the ductility. Cr is normally added to steel for increasing oxidation resistance, and ... form of graphite results in a softer iron, reduces shrinkage, lowers strength, and decreases density.
Description : Steel is composed of a number of elements. The two essential elements are iron and w) aluminum x) carbon y) nickel z) silicon
Last Answer : ANSWER: X -- CARBON
Description : Duralumin is an alloy of (A) Aluminium, copper and manganese (B) Aluminium, nickel and silicon (C) Aluminium and nickel (D) None of these
Last Answer : (A) Aluminium, copper and manganese
Description : Fire refining process is employed in case of (A) Tin (B) Copper (C) Zinc (D) Aluminium
Last Answer : (B) Copper
Description : The following type of bonding is strongly directional in solids. (A) Vander Waal's (B) Ionic (C) Metallic (D) Covalent
Last Answer : D) Covalent
Description : What is a modular system? List the important properties of a modular system.
Last Answer : Ans: A modular system consists of well defined manageable units to well defined interfaces among them. Desirable properties are Each module is a well defined subsystem useful to others Each module ... modules Modules should be easier to use than build Modules should have a simple interface
Description : State the functions of a fuse. Mention the desirable properties of fuse materials.
Last Answer : Ans: Fuse is a protective device, which consists of a thin wire or strip. This wire or strip is placed with the circuit it has to protect, so that the circuit-current flows through it. When ... silver and silver alloys are used of lower ratings. Copper alloys are used in fuses of higher ratings.
Description : Give four examples of natural insulating materials.
Last Answer : Ans: Examples of the natural insulating materials are cotton, rubber, wood, mica.
Description : Classify plastic materials into two categories, describe their important properties and give two examples of each.
Last Answer : Ans: Plastic materials can be classified into thermoplastic and thermosetting plastics. Thermoplastic materials:- The properties of these plastic materials do not change considerably if they are melted ... forming elastic threads and films. Examples are Phenol formaldehyde (Bakelite), Epoxy resins.