27. In a bipolar transistor which current is largest
28. The v-i characteristics of a FET is shown in figure. In which region is the device biased for small signal amplification
29. Secondary emission is always decremental.
30. In a degenerate n type semiconductor material, the Fermi level,
31. The types of carriers in a semiconductor are
32. 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
33. 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.
34. 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.
35. 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
36. Work function of oxide coated cathode is much lower than that of tungsten cathode.
37. The word enhancement mode is associated with
38. In which region of a CE bipolar transistor is collector current almost constant?
39. A p-n junction diode has
40. Which of the following is true as regards photo emission?
41. The power dissipation in a transistor is the product of
42. The normal operation of JFET is
43. The minority carrier life time and diffusion constant in a semiconductor material are respectively 100 microsecond and 100 cm2/sec. The diffusion length is
44. An incremental model of a solid state device is one which represents the
45. 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:
46. 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
47. Which of the following is used for generating time varying wave forms?
48. 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.
49. An one sided abrupt junction has 1021/m3 of dopants on the lightly doped side, zero bias voltage and a built-in potential of 0.2 V. The depletion width of abrupt junction.(q = 1.6 x 10-19 C, εr =16, ε0 = 8.87 x 10-12 F/m) is