59051. The temperature of cathode is increased from 2500K to 2600K. The increase in thermionic emission current is about
59052. Consider the following statement: At finite temperature, magnetic dipoles in a material are randomly oriented giving low magnetization. When magnetic field H is applied, the magnetization? Increases with HDecreases with HDecreases with temp for constant H Which of the statement given above is/are correct?
59053. Ferrites have
59054. Eg is the band gap, A is pre-factor, k is Boltzmann constant? Which one of the following is the remaining grade of paper used in paper capacitor, besides the other two grade of paper-low and extra low loss?
59055. Barkhausen criterion of oscillation is
59056. The current through a PN Junction diode with v volts applied to the P region to the N region, where (I0 is the reverse saturation current to the diode, m the ideality factor, k the Boltzmann constant, T the absolute temperature and q the magnitude of charge on an electron) is
59057. The ratio of diffusion constant for hole DP to the mobility for holes is proportional to
59058. The carrier mobility in a semiconductor is 0.4 m2/Vs. Its diffusion constant at 300k will be (in m2/s).
59059. During induction heating of metals which of the following is abnormally high?
59060. Assertion (A): Alkali metals are used as emitters in phototubes. Reason (R): Alkali metals have low work functions.
59061. The output v-i characteristics of enhancement type MOSFET has
59062. In a full wave rectifier, the current in each of the diodes flows for
59063. In an ideal junction transistor the impurity concentration in emitter (E ), base (B) and collector (C) is such that
59064. The rating of a transformer to deliver 100 watts of D.C. power to a load under half wave rectifier will be nearly
59065. When a p-n junction is forward biased, the current remains zero till the applied voltage overcomes the barrier potential.
59066. Which rectifier has the best ratio of rectification?
59067. Assertion (A): A p-n junction is used as rectifier. Reason (R): A p-n junction has low resistance in forward direction and high resistance in reverse direction.
59068. In an integrated circuit the SiO2 layers provide
59069. For a n-channel JFET with r0 = 10 kW, (VGs= 0 V, VP = - 6 V)the drain resistance rd at VGS= - 3 V is given by
59070. Which of the following are voltage controlled devices?
59071. Which of the following is known as insulated gate FET?
59072. Assertion (A): The hybrid p model of a transistor can be reduced to h parameter model and vice versa. Reason (R): Hybrid p and h parameter models are interrelated as both of them describe the same device.
59073. Which impurity atom will give p type semiconductor when added to intrinsic semiconductor?
59074. An insulator will conduct when the
59075. Zener breakdown occurs
59076. The maximum power handling capacity of a resistor depends on
59077. Epitaxial growth is used in ICs
59078. The mean life time of carrier may range from 10-9 seconds to hundreds of μ-seconds.
59079. In which mode of BJT operation are both junctions forward biased?
59080. Addition of a small amount of antimony to germanium will result in
59081. In intrinsic semiconductor magnitude of free electron and hole concentrations are equal.
59082. A P-N junction offers
59083. In modern MOSFETS, the material used for the gate is
59084. Consider the following circuit configuration common Emittercommon Baseemitter followeremitter follower using Darlington pair. The correct sequence in increasing order of I/P impedance of these configuration:
59085. Assertion (A): Field emission is substantially independent of temperature. Reason (R): When a high electric field is created at metal surface field emission may occur.
59086. In a p-n-p transistor operating in forward active mode
59087. Consider the following statements. EtchingExposure to UV radiationStrippingDeveloping After a wafer has been coated with photo resist the correct sequence of these steps in photolithography is
59088. If both the emitter base and the collector base junctions of a bipolar transistor are forward biased, the transistor is in the
59089. In a triode the potential of grid (with respect to cathode) is usually
59090. A varactor diode is
59091. Fermi level in intrinsic semiconductor is at the centre of forbidden energy band.
59092. In a photo transistor the photocurrent is
59093. In photoelectric emission the maximum kinetic energy of emitted electron is proportional to
59094. In a P-type semiconductor, the conductivity due to holes (= σP) is equal to e = charge of hole, μP = hole mobility, P = hole concentration,
59095. Hall effect is observed in a specimen when it is carrying current and is placed in a magnetic field. The resulting electric field inside the speciment will be in
59096. In P-N junction, the region containing the uncompensated acceptor and donor ions is called
59097. In a photodiode the current is due to
59098. Consider the following statements Acceptor level lies close the valence band.Donor level lies close to the valence band.n type semiconductor behaves as an insulator at 0 K.p type semiconductor behaves as an insulator at 0 K. Of these statements:
59099. If the temperature of on extrinsic semiconductor is increased so that the intrinsic carrier concentration is doubled, then
59100. Assertion (A): The conductivity of an n type semiconductor increases with increase in temperature and increase in density of donor atoms. Reason (R): Diffusion of carriers occurs in semiconductors.