Analog Electronics - 1 - May 2011

Electronics & Telecomm. (Semester 3)

TOTAL MARKS: 80
TOTAL TIME: 3 HOURS (1) Question 1 is compulsory.
(2) Attempt any three from the remaining questions.
(3) Assume data if required.
(4) Figures to the right indicate full marks. 1 A full Wave rectifier using a centre tapped transformer with two diodes gives output voltage of 250 V to a resistive load, the current being 75±25mA. If the ripple factor is 0.001, calculate the specification of the devices and components required if the filter used are-
(i) L section (LC) filter, (ii) ?- Filter and (iii) C filter. Draw complete circuit diagrams each case(20 marks) 2 (a) Design a Single stage RC coupled amplifier using FET BFW-11 biased to provide 3.5mA to achieve voltage gain of 10, lower cut of frequency of 20 Hz and to provide Vo=2.5V.(15 marks) 2 (b) For the designed amplifier find Av, Ri, Ro(5 marks) 3 (a) Determine the values of big components for CE configuration if V_CC =12V,V_CE=6V, R_C=1K, V_BE=0.6 V, h_FE=180 for the following circuits -
1. Fixed bias without R_E
2. Voltage divider biasing with V_RE=1 V (10 marks) 3 (b) Determine Q Point and draw the dc load line for the following circuit. (10 marks) 4 (a) For the following circuit, determine Av, Ri, Ro. (10 marks) 4 (b) For a CE amplifier derive the expressions for Av, AI, Zi and Zo.(10 marks) 5 (a) For the following circuit determine d.c. output voltage, ripple factor and ripple at the output Assume diodes to be ideal. (10 marks) 5 (b) What are the causes of instability of operating point of a BJT amplifier? Derive the expression for stability factor SICO for voltage divider bias circuit.(10 marks) 6 (a) For the amplifier shown in following figure, determine- 1. Gm, rd 2. Zi, Zo, Av values in each case for both with and without rd. (10 marks) 6 (b) For the following circuit, determine I_DQ and verify if the FET will operate in punch-off region. (10 marks) 7 (a) Power Mosfet-Characteristics, ratings and application.(7 marks) 7 (b) Schottkey diode-characteristics, ratings and application.(7 marks) 7 (c) UJT- Characteristics, rating and application. (7 marks) 7 (d) IGBT-Characteristics, rating and application. (7 marks)