58851. In p-n-p transistor the current IE has two components viz. IEP due to injection of holes from p-region to n-region and IE due to injection of electrons from n-region to p-region. Then
58852. In an n channel JFET, the gate is
58853. The amount of photoelectric emission current depends on
58854. Assertion (A): A p-n junction has high resistance in reverse direction. Reason (R): When a reverse bias is applied to p-n junction, the width of depletion layer increases.
58855. In the circuit of figure the function of resistor R and diode D are
58856. At very high temperatures the extrinsic semi conductors become intrinsic because
58857. When a voltage is applied to a semiconductor crystal then the free electrons will flow.
58858. Ferrite have
58859. In a p type material the Fermi level is 0.3 eV above valence band. The concentration of acceptor atoms is increased. The new position of Fermi level is likely to be
58860. In an n-p-n transistor, the majority carriers in the base are
58861. An LED has a rating of 2 V and 10 mA. It is used along with 6V battery. The range of series resistance is
58862. The number of doped regions in PIN diode is
58863. As per Indian standard,length of one link in 30 m chain should be
58864. A silicon (PN) junction at a temperature of 20°C has a reverse saturation current of 10 pico Ampere. The reverse saturation current at 40°C for the same bias is approximately.
58865. In a bipolar transistor the barrier potential
58866. Recombination produces new electron-hole pairs
58867. An amplifier without feedback has a voltage gain of 50, input resistance of 1 kΩ and output resistance of 2.5 kΩ. The input resistance of the current shunt -ve feedback amplifier using the above amplifier with a feedback factor of 0.2 is
58868. As compared to an ordinary semiconductor diode, a Schottky diode
58869. Assertion (A): When a high reverse voltage is applied to a p-n junction the diode breaks down. Reason (R): High reverse voltage causes Avalanche effect.
58870. Most suitable soil for highway embankment is
58871. Crossover distortion behaviour is characteristic of
58872. If a ac for transistor is 0.98 then βac is equal to
58873. Assertion (A): The conductivity of p type semiconductor is higher than that of intrinsic semiconductor. Reason (R): The addition of donor impurity creates additional energy levels below conduction band.
58874. In an n-p-n transistor biased for operation in forward active region
58875. An increase in temperature increases the width of depletion layer.
58876. A zener diode is used in
58877. A particular green LED emits light of wavelength 5490, Å, the energy bandgap of the semiconductor material used there is .. h = 6.6 x 10-34 J sec.
58878. In a zener diode
58879. In a bipolar transistor which current is largest
58880. The v-i characteristics of a FET is shown in figure. In which region is the device biased for small signal amplification
58881. Secondary emission is always decremental.
58882. In a degenerate n type semiconductor material, the Fermi level,
58883. The types of carriers in a semiconductor are
58884. A potential of 7 V is applied to a silicon diode. A resistance of 1 K ohm is also in series with the diode. The current is
58885. Assertion (A): The reverse saturation current in a semiconductor diode is 4nA at 20°C and 32 nA at 50°C. Reason (R): The reverse saturation current in a semiconductor diode doubles for every 10°C rise in temperature.
58886. Calculate the stability factor and change in IC from 25°C to 100°C for, β = 50, RB/ RE = 250, ΔIC0 = 19.9 nA for emitter bias configuration.
58887. A periodic voltage has following value for equal time intervals changing suddenly from one value to next... 0, 5, 10, 20, 50, 60, 50, 20, 10, 5, 0, -5, -10 etc. Then rms value of the waveform is
58888. Work function of oxide coated cathode is much lower than that of tungsten cathode.
58889. The word enhancement mode is associated with
58890. In which region of a CE bipolar transistor is collector current almost constant?
58891. A p-n junction diode has
58892. Which of the following is true as regards photo emission?
58893. The power dissipation in a transistor is the product of
58894. The normal operation of JFET is
58895. The minority carrier life time and diffusion constant in a semiconductor material are respectively 100 microsecond and 100 cm2/sec. The diffusion length is
58896. An incremental model of a solid state device is one which represents the
58897. What is the correct sequence of the following step in the fabrication of a monolithic, Bipolar junction transistor? Emitter diffusionBase diffusionBuried layer formationE pi-layer formation Select the correct answer using the codes given below:
58898. For an n-channel enhancement type MOSFET, if the source is connected at a higher potential than that of the bulk (VSB > 0), the threshold voltage VT of the MOSFET will
58899. Which of the following is used for generating time varying wave forms?
58900. Calculate the resistivity of n-type semiconductor from the following data, Density of holes = 5 x 1012 cm-3. Density of electrons = 8 x 1013 cm-3, mobility of conduction electron = 2.3 x 104 cm2/ V-sec and mobility of holes = 100 cm2/V-sec.