SRM University 2007 B.Tech Information Technology EC205 -- ELECTRONIC CIRCUITS - I - Question Paper

input RC circuit.
31. Determine the phase shift of the high frequency input RC circuit.
32. Identify the high frequency output RC circuit in a capacitively coupled
amplifier and determine the upper critical frequency of the high frequency
output RC circuit.
33. Determine the phase shift of the high frequency output RC circuit.
34. What determines the high frequency response of an amplifier?
35. If an amplifier has a mid range voltage gain of 80, the transistor’s Cbc is four pF
and Cbe = 8pF, what is the total input capacitance?
36. A certain amplifier has fc(input) = 3.5 MHz and fc(output) = 8.2MHz. Which
circuit dominates the high frequency response?
37. Draw a capacitively coupled BJT amplifier and draw the Bode plot, marking
its lower and upper critical frequencies.
38. Define Band width of an amplifier.
39. Define gain-bandwidth product.
40. Explain half-power points of an amplifier.
41. Define unity-gain frequency.
42. What is the bandwidth of an amplifier having fcL = 200Hz and fcH = 2000Hz?
43. A certain transistor has fT = 175MHz. When this transistor is used in an
Amplifier with a midrange voltage gain of 50, what bandwidth can be
achieved ideally?
44. What is the voltage gain of the amplifier at fT?
45. For the self biased E-MOSFET amplifier, identify the input and output low
frequency RC circuits.
46. What is the lower critical frequency and phase shift of the low frequency
input RC circuit?
47. What is the lower critical frequency and phase shift of the low frequency
output RC circuit?
48. Determine the values for the internal FET capacitances.
49. Draw the high frequency equivalent circuit for a JFET amplifier.
50. The data sheet of a JFET provide Ciss = 6pF and Crss = 2pF. Determine Cgd
and Cgs.
51. Draw the high frequency equivalent circuit for a JFET amplifier after
applying Miller’s theorem.
PART-B
1. Discuss the low frequency response of a BJT amplifier.
2. Express every of the subsequent ratios in dB
(a) Pout / Pin = 250 (b) Vout / Vin = 0.707 (c) Ap = 0.5 (d) Av = 100
3. A certain amplifier has a midrange rms output voltage of 10V. What is the
rms output voltage for every of the subsequent dB gain reductions with a
constant rms input voltage?
4. For an input RC circuit in a certain amplifier, Rin = 1K? and C1 = 1µf.
Neglect the source resistance.
(a) Determine the lower critical frequency

Earning:   Approval pending.