USN 15ELN15

First Semester B.E. Degree Examination, Dec.2015/Jan.2016Basic Electronics

Time: 3 hrs. Max. Marks;:::8,O1\

1

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Note: Answer any FIVE full questions, choosing one full question from each "!o~pl~.,r

Module-la. For the circuit shown in fig.Ql(a) draw the DC load line and locate Q - pti\" (04 Marks)

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Fig.Ql(a)

b. What is the need for capacitor filter? For a Half - W~~e Rectifier, explain the operation ofC - filter. (06 Marks)

c. Considering npn transistor in common emitt~ nfiguration, explain how it acts as voltageamplifier. (06 Marks)

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.~~ id R~ ~ 2 a. Explain the working of a Bridg~e'I;:ull - Wave Rectifier, with a neat circuit diagram andt; b waveforms. 11\1 \1' (06 Marks)

'"@ J5 b. Discuss the load and line '~gtilation using zener diode with neat circuit diagram and§~;?Jl ~ appropriate expressions. (06 Marks):.a ..::::~ c. Calculate the values nd Is for a BJT with Udc = 0.97 and Is = 50 /lA. Determine ~dc .

..g ~ (04 Marks)2;. ~

'§ ~ Module-2'3 ~~ 8:: 3 a. Precisely ~nalyse the circuit of voltage divider bias and hence determine the V c and VCEo§ ; Mention the Iladvantages of voltage divider bias. (10 Marks)g,~ b. Derive-an equation for output voltage for a non - inverting Op - amp. Find the gain of~ ~ amplifier if R, = 10Kn and RI = lKn. (06 Marks)@ '"E '\l'~••• <!)

~~ ORC/lOc 00 4 A base bias circuit with a 12V supply uses a transistor with hFE= 70. Design the circuit so'e :§n. a3 that Ic = 2mA and VCE= 9V (Assume RE = 0). (06 Marks)S :>° ~ b. Explain the working ofOp - amp as integrator. (05 Marks)u :>..o ~ C. Derive the expression of3 input summing amplifiers. (05 Marks)

<!)oz 5Module-3

a. Convert the fo llowing : i) 172.625(10)=( h ii) (ABCD.72)16=(iii) (1 0 1 1 1 1 0 1 .0 1 0 1)2= ( )10.

b. Perform the following operations using 1's and 2's compliment techniquei) (56)10-(79)10 ii) (23)10-(18)10.

C. State and prove de Morgan's theorem using truth table for 2 variables.(06 Marks)(04 Marks)

)8(06 Marks)

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15ELN15

OR6 a. Explain full adder circuit with truth table. Realise the circuit for sum and carry using basic

gates. Also write the diagram showing FA using two half adders. (06 Marks)b. Simplify and realize the following expressions using only NAND and NOR.

i) Y = (A + B) (B + C) ( C + B) ii) Y = AB + AC + BD + CD. (10 Marks)

Module-47 a. Explain the operation of NOR Latch with symbol, circuit and truth table.

b. With a neat block diagram, explain the architecture of 8051 microcontroller.t>(06 Marks)(10 Marks)

OR 0

8 a. How is Flip - Flop different from a Latch? Explain the gated R~~:t'lip - Flop with symbol,circuit and truth table. \i~".l:'J (08 Marks)

b. Interface stepper motor to 8051 micro controller with a p~,Atblock diagram. Explain itsworking principle. \," (08 Marks)

Module-59 a. Explain Amplitude Modulation with releva~t, waveforms. Derive the equation for

instantaneous value of modulated signal in v.R~.~rtd define modulation index. (08 Marks)b. Define the term transducer. Mention any fourbharacteristics a transducer should posess.

(02 M~rks)c. Briefly explain the working of thermi Mention its applications. (06 Marks)

ORwith necessary waveforms. Bring out the difference

(08 Marks)(08 Marks)

10 a. Explain the frequencybetween AM and FM.

b. Explain construction a-...

modulation,/»~-r·~~,·$'he principle of operation ofLVDT.

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