BSc Physics SEM VI ATKT 2018-19 ATKT Physics II Electronics 19 Old Question Paper - Mumbai University | munotes

Questions asked in this paper

• (2) Figures to the right indicate full marks

1. Q1 (a) Attempt any one:
   • (i) Discuss the construction and working of enhancement type 10 MOSFET. Draw and explain its drain characteristics and transconductance
   • (ii) | Explain the construction and working of SCR. Explain the working of half 10 wave rectifier using SCR as a rectifying device. Derive an expression for its DC output current and voltage
   • (b) Attempt any one:
   • (i) the voltage divider bias of a JFET. State and explain condition 5 under which the drain current in a voltage approximately constant for any JFET gate source voltage and drain current at the half cut off
2. Q2 (a) Attempt any one: With the help of necessary waveforms, its working and how tt is used for pulse shaping
   • (ii) With the help neat circuit diagram, explain the working of series voltage 10 feedback regulator. Derive an expression for its output voltage and power
   • (b) Attempt any one: Define and explain following terms with respect to differential amplifier, 5 and input offset voltage Explain with the help of neat circuit diagrams common mode gain. Derive 5 an expression for common mode voltage gain using emitter coupled
3. Q3 (a) Attempt any one:
   • (i) . Draw the circuit diagram of astable multivibrator using op-amp. Discuss its 10 working. Derive the expression for time period of output square wave Sketch the waveform across capacitor and at output terminal
   • (i) Draw the schematic diagram of IC 555 connected as free running 10 oscillator. Discuss its working with necessary waveforms. Derive expression for duty cycle ED29AE1247B4DC6F8A 832BE3E8CCC663
   • (b) Attempt any one:
   • (i) | What is voltage controlled oscillator? Draw the circuit diagram of voltage 5 controlled oscillator using IC its working
   • (ii) Draw the circuit diagram of Wein bridge oscillator using op-amp. 5 Calculate the oscillating frequency of Wein bridge using Ri=2KQ,
4. Q4 (a) Attempt any one: (ij) neat diagram of two inputs TTL NOR gate and explain its working. 10 Write its truth table
   • (i) Explain frequency modulation with neat diagram. What are the advantages 10 of frequency modulation over amplitude modulation?
   • (b) Attempt any one:
   • (i) the working of transistorized AM modulator with neat 5
   • (i) Draw a logic diagram of decade counter that counts in a straight binary 5 sequence. Write its truth table
5. Q5 (a) Attempt any one: (ij) JFET has a gate current of 1 nA when the reverse gate 4 voltage is 20V. What is the input resistance of the JFET? What is its ohmic resistance if Vp = 4V and Ipss = 10 mA
   • (i) has a current fusing rating of Determine the highest surge 4 current value that SCR can withstand for a period of 20 msec
   • (b) Attempt any one:
   • (i) The differential amplifier with double ended input and single ended output 4 KQ, RE = 20 KQ, If = 0.7 V for silicon transistor and Vi = V2=0 V What is the de emitter current in each silicon transistor? Find tail current and dc voltage at the output
   • (i) trigger circuit using discrete components has Vcc=12 V, 4 = 0.2V, 0.6. 10 KQ, Ro = 20 KQ and Re= 4.7 KQ. Find the values. of switching levels. and hysteresis voltage
   • (c) any one:
   • (i) A first order active high pass filter in non-inverting configuration, uses 4 R=2KQ, R=1KQ and Calculate cut-off frequency
   • (ii) monostable multivibrator is constructed using IC 555 and R=10KQ. The 4 output pulse width is 10ms. Calculate capacitance C. What will be pulse width if C is doubled? ED29AE1247B4DC6F8A 832BE3E8CCC663
   • (d) Attempt any one: (ij) | How many flip flops are required to construct each of the following 3
   • (i) with an amplitude 140 V is modulated by a signal with an 3 amplitude of 80 V. What is the percentage modulation and amplitude of ED29AE1247B4DC6F8A 832BE3E8CCC663

Read from the scan above, so a character or two may differ. The scan is the original.