Analog devices and circuits (INDSC6B) — DU B.Sc. (Hons) Instrumentation Previous Year Question Papers

Q.1 (a) Explain the working principle of IR emitter and its applications. (3) (b) Given IDss = 12 mA and Vp = -4V.Sketch the transfer characteristics for the (3) (c) An n-channel Enhancement MOSFET has Vth =2V, k = 0.5 mA/V'. (3) If Vas = 4V, calculate drain current Ip. (d) If a CMOS inverter operates at Vos = 3.3V and load capacitance is 10 pF, calculate (3) dynamic power dissipation at frequency 5 MHz. (e) A UJT relaxation oscillator uses R = 10kd and C = 100uF. (3) If ny = 0.5 and Ve = 12V, find the time period of oscillation. (f) Determine the transition capacitance of a diffused junction varicap diode at a (3) reverse potential of 4.2V. if C(0) = 80 pF and V, = 0.7V. Q.2 (a) Compare Schottky Diode and PN junction diode with characteristics and their (6) (b) Explain the working principlé of LCD and compare it with LED display. (6) (c) Describe the construction, working, characteristics, and applications of Solar Cell. (6) Q.3 (a) Explain in detail the construction, working, channel formation, pinch-off and (6) output characteristics of JFET with neat diagrams. b) Discuss different FET biasing methods and explain self-bias in detail. (6) (c) For the network circuit shown below, Determinelso and Vase. Given VoD = (6) 20V, RG1 = 910 KD, RGz = 110 KS, RD = 2.2 KS, Rs = 1.1 KS, Iss = Q.4. (a) Explain the small signal model of MOSFET. (6) (b) Explain and analyze the MOSFET Common Source amplifier and derive (6) expressions for its voltage gain, input impedance, and output impedance. (c) What is UJT? Explain the working of UJT as a relaxation oscillator. (6) Q.5 (a) Explain the working principle of a MOS inverter with diagram. (6) (b) Explain the impact of supply voltage scaling on power, delay and noise margin. (6) (c) Draw and explain the VTC of CMOS inyerter. (6) Q.6 (a) What is a thermistor? Discuss the working principle of a thermistor. A thermistor (6) has 5 kS resistance at 25°C. If temperature coefficient is -4% per °C, find its resistance at 35°C. (b) Derive the Shockley equation for JFET. (6) (c) Differentiate between JFET and MOSFET in terms of structure, operation, input (6) impedance, control mechanism, and performance parameters. Q.7 (a) Compare Resistive-Load inverter and CMOS inverter. A CMOS inverter has Von = (6) 5V, VI = 3.5V, VIL = 1.5V, Vor = OV.Calculate Noise Margin High (NMH) and Noise Margin Low (NML). (b) Explain in detail the principle of operation and V-I characteristics of Tunnel Diode (6) with neat diagram. (c) For the network circuit shown below, sketch the ac equivalent network and (6) calculateZ;, Zo and Ay. Given Vaso = 0.35 V and IDa = 7.6 mA.