Description : In a conductor – (1) there is no conduction band (2) the forbidden energy gap is very wide (3) the forbidden energy gap is very narrow (4) the valence band and the conduction band overlap each other
Last Answer : (4) the valence band and the conduction band overlap each other Explanation: In the case of a conductor, there is no forbidden energy gap. The conduction and valence energy bands overlap ... , the electrons from the valence band can freely enter the conduction energy band. Conduction energy band
Description : In a conductor (1) there is no conduction band (2) the forbidden energy gap is very wide (3) the forbidden energy gap is very narrow (4) the valence band and the conduction band overlap each other
Last Answer : the valence band and the conduction band overlap each other
Description : Magnetic materials (A) provide path to magnetic flux. (B) are good insulators. (C) are semiconductors. (D) None.
Last Answer : (A) provide path to magnetic flux.
Description : Holes are majority carriers in (A) P-type semiconductors. (B) N-type semiconductors. (C) Insulators. (D) Superconductors.
Last Answer : (A) P-type semiconductors.
Description : Ceramics are good (A) insulators. (B) conductors. (C) superconductors. (D) semiconductors.
Last Answer : (A) insulators.
Description : n-type semiconductor is an example of (A) extrinsic semiconductor. (B) intrinsic semiconductor. (C) super conductor. (D) insulators..
Last Answer : (A) extrinsic semiconductor.
Description : Atoms with four valence electrons are good conductors. (A) True (B) False
Last Answer : (B) False
Description : Germanium possesses (A) one valence electrons. (B) two valence electrons. (C) three valence electrons. (D) four valence electrons.
Last Answer : (D) four valence electrons.
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 : For germanium the forbidden gap is (A) 0.15ev. (B) 0.25ev. (C) 0.5ev. (D) 0.7ev.
Last Answer : (D) 0.7ev.
Description : Fire refining process is employed in case of (A) Tin (B) Copper (C) Zinc (D) Aluminium
Last Answer : (B) Copper
Description : Large scale integration chips have between (A) Less than 10 components. (B) 10 and 100 components. (C) 100 and 1000 components. (D) More than 1000 components.
Last Answer : (C) 100 and 1000 components.
Description : Define conduction band & forbidden energy gap.
Last Answer : Conduction band :Range of energy possesed by conduction electrons is called conduction band. Forbidden energy gap : The energy difference between conduction band and valance band is called forbidden energy gap.
Description : For conductors, the free electrons will exist at a) Valence band b) Middle of valence and conduction band c) Will not exist d) Conduction band
Last Answer : d) Conduction band
Description : Materials which can store electrical energy are called (A) magnetic materials. (B) semi conductors. (C) dielectric materials. (D) super conductors.
Last Answer : (C) dielectric materials.
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.
Description : Ferroelectric materials are characterised by (A) Very high degree of polarisation. (B) A sharp dependence of polarisation on temperature. (C) Non-linear dependence of the charge Q on the applied voltage. (D) All the above.
Last Answer : (D) All the above.
Description : Tick of the property, which is different from the group (A) Ductility. (B) Resistivity. (C) Tensile strength. (D) Hardness.
Last Answer : (B) Resistivity
Description : Tick off the material, which is different from the group (A) Constantan. (B) Manganin. (C) Nichrome. (D) Brass.
Last Answer : (D) Brass.
Description : Semi-conductors have ________ temperature coefficient of resistance. (A) Negative (B) Positive (C) Both positive and negative (D) None of the above
Last Answer : (A) Negative
Description : Hysteresis loss least depends on (A) Frequency. (B) Magnetic field intensity. (C) Volume of the material. (D) Grain orientation of material.
Last Answer : (D) Grain orientation of material.
Description : Paper is hygroscopic and absorbent. (A) True (B) False
Last Answer : (A) True
Description : In a ferromagnetic material the state of flux density is as follows when external magnetic field is applied to it. (A) Increased (B) Decreased (C) Remains unchanged (D) Becomes zero
Last Answer : (C) Remains unchanged
Description : Addition of trivalent impurity to a semiconductor creates many (A) holes. (B) free electrons. (C) valance electrons. (D) bound electrons.
Last Answer : (B) free electrons.
Description : Hall effect is associated with (A) Conductors. (B) Semiconductors. (C) Thermistors. (D) Solders.
Last Answer : (B) Semiconductors.
Description : Hard magnetic materials are used for making (A) Permanent magnets. (B) Temporary magnets. (C) Conductors. (D) Insulator.
Last Answer : (A) Permanent magnets.
Description : Example of high resistivity material is (A) Nichrome (B) Silver (C) Gold (D) Copper
Last Answer : (A) Nichrome
Description : A transistor has (A) One p-n junction. (B) Two p-n junction. (C) Four p-n junction. (D) Five p-n junction.
Last Answer : (B) Two p-n junction.
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 : Which of the following material has the highest melting point (A) Copper. (B) Aluminium. (C) Tungsten. (D) Gold.
Last Answer : (C) Tungsten.
Description : Number of Terminals in a MOSFET are (A) Two (B) Three (C) Four (D) Five
Last Answer : (B) Three
Description : When a semiconductor is doped with a P-type impurity, each impurity atom will (A) acquire negative charge. (B) acquire positive charge. (C) remain electrically neutral. (D) give away one electron.
Last Answer : (A) acquire negative charge.
Description : The conductivity of an extrinsic semiconductor (A) decreases with temperature. (B) increases with temperature. (C) remains constant with temperature. (D) decreases and then increases with temperature.
Last Answer : (B) increases with temperature.
Description : P-N junction is (A) a rectifier. (B) an amplifier. (C) an Oscillator. (D) a Coupler.
Last Answer : (A) a rectifier.
Description : What is the type of bonding in silicon? (A) Ionic. (B) Covalent. (C) Metallic. (D) Ionic + Metallic
Last Answer : (B) Covalent.
Description : Micanite is a form of (A) Built up mica. (B) Hydrated potassium aluminium silicate. (C) Magnesium mica. (D) Calcium mica.
Last Answer : (A) Built up mica.
Description : The main constituents of glass is (A) SiO2 (B) B2O3 (C) Al2O3 (D) Cr2O3
Last Answer : (A) SiO2
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 : Aluminium is (A) Silvery white in colour. (B) Yellow in colour. (C) Reddish in colour. (D) Pale yellow in colour.
Last Answer : (A) Silvery white in colour.
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 : The most malleable, ductile low resistivity material is (A) Copper. (B) Aluminium. (C) Silver. (D) Iron.
Last Answer : (C) Silver.
Description : The heating elements of electric irons are made of (A) Copper. (B) Nichrome. (C) Constantan. (D) Aluminium.
Last Answer : (B) Nichrome.
Description : Barrier potential in a P-N junction is caused by (A) Thermally generated electrons and holes. (B) Diffusion of majority carriers across the junction. (C) Migration of minority carriers across the junction. (D) Flow of drift current.
Last Answer : (B) Diffusion of majority carriers across the junction.
Description : In order to obtain p-type germanium it should be doped with a (A) Trivalent impurity. (B) Tetravalent impurity. (C) Pentavalent impurity. (D) Any of the above will do.
Last Answer : (A) Trivalent impurity.
Description : Plastics are (A) Good conductors of heat. (B) Good conductors of electricity. (C) Bad conductors of electricity. (D) High density.
Last Answer : (C) Bad conductors of electricity.
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.