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 : Constantan is an alloy of (A) Cu (55%) & Sn (45%) (B) Cu (55%) & Ni (45%) (C) Pt (95%) & Rh (10%) (D) Fe (80%) & Ni (20%)
Last Answer : (B) Cu (55%) & Ni (45%)
Description : Maraging steels derive their strength from the following mechanism: (A) A fine, highly dislocated and strong martensite (B) Fine dispersions of inter-metallic of Fe, Ni, Ti etc (C) Fine ... alloy carbides in a ferrite matrix (D) Fine dispersions of Fe3 C nucleated on dislocations in austenite
Last Answer : Option A
Description : Transformer cores are laminated with (A) Low carbon steel. (B) Silicon sheet steel. (C) Nickel alloy steel. (D) Chromium sheet steel.
Last Answer : (B) Silicon sheet steel.
Description : Which one of the following has a square planar geometry? `(Co=27, Ni=28, Fe=26, Pt=78)`
Last Answer : Which one of the following has a square planar geometry? `(Co=27, Ni=28, Fe=26, Pt=78)` A. `[NiCl_(4)]^(2-) ... `[CoCl_(4)]^(2-)` D. `[FeCl_(4)]^(2-)`
Description : Among the following complexes : `K_(3)[Fe(CN)_(6)],[Co(NH_(3))_(6)]Cl_(3)` , `Na_(3)[Co ( o x )_(3)],[Ni(H_(2)O)_(6)]Cl_(2)`, `K_(2)[Pt(CN)_(4)]` and
Last Answer : Among the following complexes : `K_(3)[Fe(CN)_(6)],[Co(NH_(3))_(6)]Cl_(3)` , `Na_(3)[Co ( o x )_(3)],[Ni(H_( ... ,M,N B. K,N,O,P C. L,M,O,P D. L,M,N,O
Description : Newlands' table, the elements were placed with the halogens - (1) Mn and As (2) Fe and Se (3) Ce and La (4) Co and Ni
Last Answer : (4) Co and Ni Explanation: Newlands' Law of Octaves suffered from lot of limitations, In order to fit elements into his table, Newlands ad justed two elements in the same slot, but also put some unlike elements under the same note.
Description : A complex compound in which the oxidation number of a metal is zero is - (1) K4 [Fe (CN)6] (2) K3 [Fe (CN)6] (3) [Ni (CO)4] (4) [Pl (NH3)4]Cl2
Last Answer : (3) [Ni (CO)4]
Description : The deficiencies of micronutrients, not only affect growth of plants but also vital functions such as photosynthetic and mitochondrial electron flow. Among the list given below, which group of three elements shall affect most, both ... , Mo (b) Ca, K, Na (c) Mn, Co, Ca (d) Cu, Mn, Fe
Last Answer : d) Cu, Mn, Fe
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 : 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 : Secondary hardening in steels arises out of the (A) Precipitation of fine alloy carbides at high temperatures (B) Refinement of ferrite grain size by working (C) Decomposition of retained austenite upon heat treatment (D) Precipitation of complex inter-metallic upon heat treatment
Last Answer : Option C
Description : Which of the following metals is used in Space Crafts to withstand high temperatures? (1) Fe (2) Ti (3) Ni (4) Pb
Last Answer : (2) Ti Explanation: Titanium alloy, which has high corrosion resistance, high specific strength, and good heat resistance, is used for different spacecraft parts including outer fuel tank sheathing and wings. It is extremely strong at high temperatures.
Description : Which of the following metals is used in Space Crafts to withstand high temperatures ? (1) Fe (2) Ti (3) Ni (4) Pb
Last Answer : Ti
Description : Low pressure Zeigler process for the manufacture of polythene uses a catalyst which is (A) Ni (B) V2O5 (C) Fe (D) Aluminium triethyl combined with titanium tetrachloride
Last Answer : (D) Aluminium triethyl combined with titanium tetrachloride
Description : Consider the production of ammonia from methene and air as raw materials. The catalysts used are: (i) __________ for steam reforming of methane and (ii) __________ for ammonia synthesis. (A) (i) - Ni/Al2O3 ; (ii) - Cu - ZnO/ ... (i) - Ni/Al2O3 ; (ii) - Fe/Al2O3 (D) (i) - Fe/Al2O3 ; (ii) - Ni/Al2O3
Last Answer : (C) (i) - Ni/Al2O3 ; (ii) - Fe/Al2O3
Description : The trace metal present in insulin is (A) Cu (B) Zn (C) Fe (D) Ni
Last Answer : (B) Zn
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 : 19 Transformer cores are built up from laminations rather than from solid metal so that A. Oil penetrates the core more easily B. Eddy current loss is reduced C. Less lamination is required for the windings D. Turn ratio is higher than voltage ratio
Last Answer : B. Eddy current loss is reduced
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 : Those magnetic materials are best suited for making armature and transformer cores which have____permeability and_______hystersis loss.
Last Answer : Those magnetic materials are best suited for making armature and transformer cores which have high permeability and low hystersis loss.
Description : Other parameters remaining same, the recrystallisation temperature of an alloy is lowered, when (A) Strain rate is increased (B) Grain size is increased (C) Prior cold deformation is increased (D) Not affected by any of the above parameters
Last Answer : (A) Strain rate is increased
Description : Which of the following has highest melting point? Ni, Fe, Pt, W. -Chemistry 9th
Last Answer : i think all are equal
Description : The correct statement (s) regarding the binary transition metal carbonyl compounds is (are) (Atomic numbers: Fe = 26, Ni = 28)
Last Answer : The correct statement (s) regarding the binary transition metal carbonyl compounds is (are) (Atomic ... the oxidation state of the metal is increased
Description : The catalyst used in hydrogenation of oils is - (1) Fe (2) V2O5 (3) Ni (4) O2
Last Answer : (3) Ni Explanation: The catalyst used in hydrogenation of oils is nickel. It is used to speed up the reaction. Vegetable oils convert into vanaspati after hydrogenation.
Description : The core metal of chlorophyll is (a) Ni (b) Cu (c) Fe (d) Mg.
Last Answer : d) Mg.
Description : Which of the following is universally employed as the low expansion metal in the bimetallic thermometer, which is an iron-nickel alloy containing 36% nickel and has very low co-efficient of expansion (1/20th of ordinary metals) ? (A) Invar (B) Constantan (C) Chromel (D) Alumel
Last Answer : (A) Invar
Description : In transformer, the core is made up of soft iron in order to pass the maximum A. flux B. current C. magnetic flux D. voltage
Last Answer : magnetic flux
Description : Radioactive materials should be kept in the container made of : (1) Fe (2) Al (3) Pb (4) Steel
Last Answer : (4) Steel Explanation: Radioactive materials are first encased in resin or concrete and sealed in steel drums. The drums are then packed into concrete casks and placed in concrete trenches up to 18 metres deep.
Last Answer : Steel
Description : Sino si Charles Darwin ano ang pinakamalahasang kontribusyon ni Charles Darwin ng agham?
Last Answer : Nakakaloka
Description : Bakit iniligtas ni aldin si florante gayong maghigpit na magkalaban ang kanilang lahi?
Last Answer : Feel Free to Answer
Description : Bakit tumanggi si basilio sa alok ni simoun na paghihimaksik sa mga kastila?
Last Answer : What is the answer ?
Description : Ano ang dahilan ni gavrilo prinsip upang patayin si archduke franz fernandez?
Last Answer : Need answer
Description : Which of the following relations is correct? a) NI = Sφ b) NS = Iφ c) Nφ = SI d) NI = S/φ
Last Answer : a) NI = Sφ
Description : Purity of coke means that, it is high in carbon and low in (A) Volatiles (B) Ash (C) Iron (D) Moisture
Last Answer : (A) Volatiles
Description : For 275 kV transformers, using cold rolled grain oriented steel, which of the following values of flux density may be used? (a) 1.0 Wb/m2 (b) 1.1 Wb/m2 (c) 1.3 Wb/m2 (d) 1.6 Wb/m2 (e) None of the above
Last Answer : (d) 1.6 Wb/m2
Description : The cold rolled grain oriented steel has ______ permeability in the direction of the grain orientation. (a) minimum (b) maximum (c) nil (d) none of the above
Last Answer : (b) maximum
Description : The orbitals of iron involved in the hybridization in `Fe(CO)_(5)` are
Last Answer : The orbitals of iron involved in the hybridization in `Fe(CO)_(5)` are A. `s,p_(x),p_(y),P_(z) and d_(x^(2)- ... (x),p_(z),P_(xy) and d_(x^(2)-y^(2))`
Description : What holds grain that starts with si?
Last Answer : Sifter
Description : German Silver is an alloy of------? A. Zn + Ni B. Cu + Zn C. Cu + Ni (Answer) D. Cu + Sn E. None of these
Last Answer : C. Cu + Ni (Answer)
Description : Rotary driers are generally made of (A) Cast iron (B) Mild steel (C) High silicon iron (14% Si) (D) Tin lined with refractory bricks
Last Answer : (B) Mild steel
Description : The 'bomb' in the bomb calorimeter is made of (A) Molybdenum stainless steel (B) Mild steel (C) High silicon iron (14% Si) (D) Copper
Last Answer : (A) Molybdenum stainless steel
Description : Copper is dissolved from its ore by H2SO4 in a percolation tank made of (A) Wood (B) Stainless steel (C) Reinforced concrete lined with lead (D) High silicon iron (14% Si)
Last Answer : (C) Reinforced concrete lined with lead
Description : Carbon tetrachloride can be stored in a storage vessel made of (A) High silicon iron (14% Si) (B) Tin (C) Stainless steel (D) All (A), (B) and (C)
Last Answer : (D) All (A), (B) and (C)
Description : Containers made of high silicon cast iron (14% Si) are not suitable for the storage of (A) Acetic acid (B) Benzoic & boric acids (C) Phosphoric acid (95%) & sulphuric acid (95%) (D) Hydrochloric acid (concentrated)
Last Answer : (D) Hydrochloric acid (concentrated)
Description : Which of the following is not an alloy of tin? (A) White-bearing metal (B) Pewter type metal (C) Soft solder (D) German silver
Last Answer : (D) German silver
Description : Which of the following is heaviest metal? Pb, As, Al, Ni -Chemistry 9th
Last Answer : lead(pb) hope this helps u