T188-EDC(1)

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T188-Electronic Devices & circuits

Q.No Description Marks

1. a) Explain the working of a PN diode in forward and reverse conditions.b)Explain how a PN junction diode acts as a Rectifier and Mention the Applications

of PN iode . !Rc) erive an expression for "ontinuit# E$uation.

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2. a) erive the current e$uation of a PN diode.

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b) "alculate the +ilicon diode current for a ,orward bias voltage of -.( at /0-" 1 if the reverse saturation current is /-2A.

c) Explain 3all Effect and describe its applications.

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3. a) Explain about 4ransition capacitance and obtain the expression for it.

b) 4he diode current is -.05A1 when the applied voltage is 6--5 and /-5A1 when

the applied oltage is *--5. eter5ine 7.!R

c) Explain the 89 characteristics of a 4unnel diode with a circuit diagra5.

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4. a) erive an expression for ,er5i8level in 9ntrinsic and Extrinsic :both P and N

t#pe) +e5iconductors.

b) Explain the effect of te5perature on diode characteristics.!R

c) 4he current flowing in a PN diode at roo5 te5perature is /-;-80A1 whena large reverse bias is applied. "alculate the current flowing when -.& is applied.

d) Explain about iffusion capacitance and obtain the expression for it.

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5. a) iscuss the

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c),or a full G wave rectifier circuit shown in figure 1 deter5ine

:i) " output voltage1:ii) P91:iii) Rectification effe5inac#.

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10. a) erive the Expressions for the following para5eters of the 3?R circuit. a) Average " current b) Average " voltage c) R.M.+ value of current

d) " power output e) A" power input f) Efficienc# g) Ripple factor

!Rb) ?h# filter circuit is necessar# with rectifiers. >ist the different filters used with their

5erits and de5erits.c) Explain how Cener regulator works under var#ing input voltage conditions.

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11. a) efine H1 I and J of a transistor and obtain the relation between the5.

b) Explain the construction of K,E4 with neat diagra5!R

c) raw the circuit diagra5 of NPN transistor "E configuration and explain its operation

with the help of input and output characteristics.

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12. a) ?ith the help of neat sketches and characteristic curves explain the operation of the

Kunction ,ield Effect 4ransistor.b) efine rd1 g5and 2 of K,E4 and obtain the relation between the5.

!Rc) 9f the base current in a transistor is --2A when the e5itter current is /* 5A. ?hat

are the values of H and I Also calculate the collector currentd) ?rite short notes on BK4.

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13. a) raw the circuit to obtain drain and transfer characteristics for an n8channelK,E4.Explain its operation with the help of these characteristics.

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b) ?hat are the differences between arge signal current gain

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14. a) raw the circuit diagra5 of PNP transistor "< configuration and explain its operation

with the help of input and output characteristics.!R

b) ?hat are the differences between K,E4 and M!+,E4.c) ?rite short notes on +"R

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15. a) erive the EberLs8Moll e$uations of a transistor.!R

b) Explain the constructional features of a depletion 5ode M!+,E4 and explain its basic

operation.c) ?hat is Earl#8Effect or base8width 5odulation.

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b) raw a transistor +elf G

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18. a) raw a transistor "ollector8to8 /--F. 4he h8para5eters are hie ./ F1 hre /;-861 hfe 0- and

hoe /*2A. "o5pute the current gain A91 input resistance Ri1 voltage gain A and output

resistance Rousing exact anal#sis and approxi5ate anal#sis.

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b) a) raw h8para5eter 5odel of a "< transistor and derive expressions for

i)input i5pedance ii)voltage gain iii) current gain iv)output i5pedance

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23. a) A transistor used in a "" "ircuit is shown in ,igure with the following set ofh para5eters.hic / F1 hfc 8*1 hrc 1 hoc /* Q -0

,ind the values of input and output resistances1 current and voltage gains of the

a5plifier stage. Bse the approxi5ate anal#sis.

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b) "o5pare the "

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24. a) A "< a5plifier driven b# a source of internal resistance Rs 0--F and the load

i5pedance is R> /--F. 4he h8para5eters are h ib //F1 hrb 6;-861 hfb 8-.@& and hob

-. /*2A. "o5pute the current gain A91 input resistance Ri1 voltage gain A1 overall

currentgain A9+1 overall voltage gain A+and output resistance Rousing exact anal#sis and

approxi5ate anal#sis.!R

b) A "E a5plifier has transistor with h8para5eters hie . F1 hre /*;-861 hfe -- andhoe /*2A."o5pute A91 Ri1 A1A+and Rowith R>/F and Rs- F.

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25. a) raw the circuit diagra5 of "" a5plifier and explain its working.

b) ?rite short notes on !scillators.!R

c) A E5itter ,ollower circuit using a transistor has the following h8para5eters h ie F1 hre

/*;-861 h fe /-- and hoe /*2A. "o5pute A91 Ri1 A1A+and Rowith R>6F and

Rs F.using Exact and approxi5ate anal#sis.

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