Semiconductors Questions and Answers

c In case of a lifting machine efforts required to lift loads of 50 N and 80 N were 12 N and 18 N respectively If velocity ratio for the machine was 6 determine 1 relation between the load and effort ii the efficiency of the machine and the effort lost in friction at 50 N load iii the maximum efficiency which can be expected from this machine

Evaluate the position of Fermi level in p and n type semiconductor in detail by depicting the position of donor and acceptor ion levels Show the occupancy of states at 0 K temperature and above 0 K temperature diagrammatically using distribution function Use the editor to format your answer

The battery is charged from full wave rectifier fed by a sinusoidal voltage see figure Ideal diodes ammeter and voltmeter show the time average value At idle with only key K closed voltmeter shows 12 V and current is then absent ie reading of ammeter is 0 If only the key K is closed the voltmeter shows battery voltage at 12 3 V During charging when the K and K are closed the voltmeter shows 12 8 V and ammeter shows 5 A Find the internal resistance of battery K A K P V

In N type semiconductor the fermi level lies 0 3 eV below the conduction band at 300 K if the temperature is increased to 330 K determine the new position of the fermi level Evaluate the value of Fermi Dirac function for intrinsic semiconductors

I Dielectric 11nd Dielectric Surface charge density on the upper metallic plate QA Area of plate A d 3 D Total K 3 K 5 OB 24 3 5 A The ratio of energy density in Ist dielectric to second dielectric is 3 3 B The ratio of energy density in Ist dielectric to second dielectric is 5 30 C Total induced surface charge density on the interface of the two dielectric is 15 26

re tap ave rectifier b Solve and find the following parameters for the fixed bias conf R 470K R 2 2K B 100 Vcc 18V VBE 0 7V CC Ic ii iii VCE VE iv given i IB Vc v 5

For the Silicon BJT circuit shown in Fig below RB 100K Given VBB 5V and Vcc 15V If B 50 then calculate IB IC IE and VCE e IC BIB is applicable in active region In e region typically 2V VBB RB BL E RC Vec Ans IB 43 A IC 2 15mA IE 2 193mA VCE 12 85V

Sir please explain reason why 1 st option of correct Please don t copy paste old answe rs Semiconductor Diode 13 In a semiconductor diode the reverse biased current is due to drift of free electrons and holes caused by 1 Thermal excitations only 2 Impurity atoms only 3 Both 1 2 0 Neither 1 nor 2

8 Newton s rings are observed in reflected light of wavelength 6000A with a liquid b w the plane and curved surface If the diameter of the 6th bright ring is 3 1mm and the radius of curvature of the curved surface is 1m calculate the refractive index of the liquid

12 5 mA 15 5 mA A Calculate the current through the Zener diode with a load resistance of 1k0 1 Point 14 7 mA 13 8 mA URE 12 t V 51V

16 1 mA A silicon diode is connected in series with the resistor R1 determine the current flowing through the diode 1 Point 20 6 mA 11 3 mA V1 12V 24 9 mA 1k0 D1 1N4001

Determine the RLmin where RS 1K0 Vin 50V VZ 10V 1 Point 500 300 0 100 2 700 Q Rs 99 R 11 O ENG IN d 110

4 Zero 10 If for a transistor A 20 mA and A 1 mA The value of a is Symbols have usual meanings B 50 to 19 21 21 20 Fill in the Blanks 3 2 4 21 19 20 21 1 50 6mm gb SK

biased 4 Both 1 and 2 For a transistor current amplification factor is 50 while working in common emitter configuration The change in base current when collector current changes by 6 mA is i so 1 120 A 2 50 A collector Current chan 3 90 A 4 Zero 6mm 10 If for a transistor 9 23 Which of the two c

3 Two similar blocks of intrinsic silicon are separately Pre Medical Physics doped uniformly to obtain same dopant densities NDNA per m The n type and p type samples thus obtained are arranged in parallel to each other and a current is passed through the combination Then 1 same current passes through each sample 2 current through n type sample is more 3 current through p type sample is more 4 current through p type sample is twice that thro

In an n type semiconductor the Fermi level lies 0 4 eV below the conduction band If the concentration of donor atoms is doubled find the new position of the Fermi level w r t conduction band 1 T

GE PN junction is connected to an external power supply the junction is said to be forward options Marks 1 Emission of light occurs due to OPTIONS Generation of hole and electrons in reverse biasing Generation of hole and electrons in forward biasing Recombination s of hole and electrons in reverse biasing Recombination s of hole and electrons in forward biasing

lone pair JC s both the species hav y b c d 40 9 sp OS S C 4 AB 35 In the given circuit Vo and Vo are Si 12 V 1 11 3 V and 0 3 V 2 0 3 V and 11 3 V 3 11 3 V and 11 3 V 4 0 3 V and 0 3 V Vo 4 7 ks2 ww Ge V02 Scale reading E Scale reading 2

For the given transistor the current gain is 200 The potential difference across base collector Junction VCB is 20 V 360 ko www O 1 V O 13 V O 4 V O2V www 1 ke 4 Ic 2 5 mA

View In English A zener diode has a contact potential of 1 V in the absence of biasing It undergoes Zener breakdown for an electric field of 10 v m at the depletion region of p n junction If the width of the depletion region is 2 5 um what should be the reverse biased potential for the Zener breakdown to occur 1 2 3 4 Correct Answor 2 Your Answer 3 Status incorrect 3 5 V 2 5 V 15 V 0 5 V

35 2 A 3 A B 4 AB In the following circuit of PN junction diodes D D and D are ideal then I is R ww I 1 E R 2 E 2R 3 2E 3R D D D E R www www R 1 A 3 A B 35 frent q D 14 1 E R 2 E 2R 3 2E 3

A common emitter amplifier is used to amplify input V 4sin 200 m If voltage gain is A 5 then output Vois O 20sin 200 TT O 20cos 200 m O 20sin 200 TT O 20cos 200 m

a P type Q 16 When a battery is connected to semiconductor with a metallic wire the curren in the semiconductor predominantly inside th metallic wire and that inside the battery respectivel due to 1 Holes electrons ions 2 Holes ions electrons 3 Electrons ions holes holes

Reverse break down voltage for silicon diode is 6V for a particular doping concentration and forward break down voltage is 0 3V then find approximate current through battery in the given circuit 1002 O 2 Amp O 1 3 Amp 1002 www 10

In a very long p type Si bar with cross sectional area 0 5 cm N 10 cm3 we inject holes such that the steady state excess hol centration is 5 x 10 6 cm3 at x 0 What is the steady state separ between F and E at x 1000 A What is the hole current there

55 A zener diode of 40 V breakdown is connected in series with a resistance of 200 2 If a load of 2 k is connected across the zener diode over what range of input voltage will the circuit operate Given the maximum zener current is 25 mA 1 40 V to 44 V 2 40 V to 49 V 3 44 V to 49 V 4 42 V to 52 V

18 ALLEN Carbon Silicon and Germanium atoms have four 18 fferant ac fags vary as agizian 8 574 valence electrons each Their valence and conduction bands are separated by energy band gaps represented by E E and Ege respectively Which one of the following relationships is true in their case 1 Eg c Eg 3 E Eg si 2 Eg e Eg si 4 E c E si E E si E Gerefeta fara na teren 1 Eg c Epe 3 E E si 2 Eg e E si 4 E E si

5 A scientist attempts to replace a few carbon atoms in 1 0 g of diamond with boron atoms or nitrogen atoms in separate experiments Which of the following is correct A The resulting material with B doping will be an n type semiconductor B The resulting material with B doping will be a p type semiconductor C B doping is not possible as B cannot form multiple bonds D The resulting material with N doning will be a n type semiconductor

kinetic energy acquired by proton is 1 MeV the energy acquired by the alpha particle will be 1 1 MeV 2 4 MeV 3 0 5 MeV 4 1 5 MeV In a common emitter transistor circuit the base 26 current is 40 A then VBE is Vr 10 V 1 2 V 245 kn 2KO Ic 2 0 2 V 3 0 8 V 4 Zero 33f gft 1 1 MeV 3 0 5 MeV 1 MeV at HAVBE BITT 245 kn 2 4 MeV 4 1 5 MeV fer fram 40 V 10 V 240 1 2V 2 0 2 V 3 0 8 V 4

Ho I 3 x 2 j 4 4 r A B In the following circuit the output Y for all 8 possible inputs A and B is expressed by the truth table 1 ABY 001 011 101 110 3 ABY 000 1 1 0 Ho I 4x r 101 x 2 j B 2 ABY 001 010 100 110 4 ABY 000 0 1 0 1 00 111 Y 3 Ho I 4x r x 2 j 4 aruit and referen wat A B 1 ABY 001 011 101 110 3 ABY 000 01 1 1 0 1 Ho I AF 2 j a f n fer fr a y B 2 ABY 00 1 0 1 0 1 0 0 1 1 0 4 AB Y 0 0 0 0 1 0 1 0 0 1 1 1

ALLEN The diode used in the circuit shown in the 29 figure has a constant voltage drop of 0 5 V at all currents and a maximum power rating of 100 milliwatts What should be the value of the resistor R connected in series with the diode for obtaining maximum current R 0 5V 1 5V KH E fa fard y 150 100 fac at x fer 31416 vilem 4 3 ufaju R ferd srits fava 0 5 Vo R ww 1 5V 0 5V KH

central maxima of single slit pattern 1 0 1 mm 2 0 4 mm 3 0 02 mm 4 0 2 mm An N P N junction in a common emitter mode is 27 used as a simple voltage amplifier with a collector current of 4mA The terminal of 8 V battery is connected to a collector through a load resistance R and to the base through a resistance RB The collector emitter VCE 4V base emitter voltage VBE 0 6 V and base current amplification factor Bac 100 Find values of R and RB 1 R 1 k and R 185 k 2 R 2 k2 and Rg 150 k 3 R 1 k2 and Rg 240 km2 4 R 3 k2 and R 185 kQ 1 1 0 1 mm 3 0 02 mm 2 0 4 mm 4 0 2 mm N P Nay una cuda a 4 MATER ft R aleed VBE 0 6 Bc 100 cal VCE B 1 R 1 2 R 2 k2 3 R 1 K2 Rg 240 k 4 R 3 kQR 185 KO R185 k RB 150 k 8 v 4V 3 32 dar

2 4 NOR In Re Vcc 10 V VCE 5V Re 1 k VBE Zero B 100 R 1 50 k 3 200 k 2 100 k 4 20 k 12 4 NOR Re Vcc 10 V VCE SV Rc 1 k VBE Zero B 100 R 1 50 k 3 200 k 2 100 k 4 20 k

possibly inside the unknown block M E New O positive clamper O positive clipper Onegative clamper Onegative clipper The reverse saturation current of a silicon diode is 3 nA at 27 deg Celsius Find the reverse saturation current at 82 deg Celsius O 136 nA 73 9 NA O 320 UA 7 9 UA

As the reverse voltage applied to the varactor diode increases its capacitance decreases Why Differentiate LED and Photodiode Zener diodes are commonly used in voltage regulators Why

Zener Diode Varactor Diode LED Photodiode Schottky Diode PIN Diode Tunnel Diode Current regulator Diode Rectifier Diode Signal Diode Shockley Diode

When a P N junction is connected to an external power supply the junction is said to be forward biased Read the following passage to answer the given questions based on it Choose the correct options Marks 1 Emission of light occurs due to OPTIONS Generation of hole and electrons in reverse blasing Generation of hole and electrons in forward biasing Recombination s of hole and electrons in reverse biasing Recombination s of hole and loc

InSb is an intrinsic semiconductor with energy gap of 0 15 ev A hall voltage of 4 07 mV is developed across 1 cm 1 mm 1mm bar of InSb when a current 1 0 1 A passes along x direction in the presence of magnetic induction 0 1 Wb m 2 along z direction Read the following passage to answer the given questions based Choose the correct options Marks 2 What will be the Hall coefficient if current is increased to 0 5 A OPTIONS 4 14 10 5 m 3 CA 1 8 14 10 5 m 3 C 1 4 07 10 5 m 3 CA 1

In the given circuit diagram if ideal ammeter connected between point A and B its reading is 5A if ammeter of resistance 322 is connected between A and B its reading is 3A Reading of ideal voltmeter is 90 n volt if it is connected between A and B then fill the value of n R R R www R B R ww R R

89 When an n p n transistor is used as a C E amplifier ther AIIMS 1999 a holes move from emitter to base b electrons move from base to collector c holes move from base to emitter d electrons move from collector to base

O ar as wel pla 3 11 3 V and 11 3 V 4 0 3 V and 0 3 V 36 For a common emitter amplifier the audio signal voltage across the collector resistance 2 k2 is 2 V If the current amplification factor of the transistor is 200 and the base resistance is 1 502 then base current is 1 10 A B 2 1 A 3 1 mA 3 x B Ic 3 2

The transistors provide good current amplificati when they are used in X 1 Common collector amplification 2 Common emitter configuration 3 Common base configuration amplification

a semiconductor device kt 4 co 45 sents B MA usion haracteristic for 11 25 141X 10 2 Pros 3 1 x 2 Which of the following statement is correct 1 It is V I characteristic for solar cell where point A represents open circuit voltage and point B short circuit current 2 It is for a solar cell and point A and B represent open circuit voltage and current respectively 3 It is for photodiode and points A and B represent open circuit voltage and current respectively 4 It is for a LED and points A and B represent open circuit voltage and short circuit current

kt k co 45 de The given graph represents V I characteristic for a semiconductor device MA B 11 2 114x10 1 1 2 3 1 0x 109 1 4x108 Which of the following statement is correct 1 It is V I characteristic for solar cell where point A represents open circuit voltage and point B short circuit current 2 It is for a solar cell and point A and B represent open circuit voltage and current respectively 3 It is for photodiode and points A and B represent open circuit voltage and current respectively 4 It is for a LED and points A and B represent open circuit voltage and short circuit current

1 The equilibrium electron concentration in Si at room temperature is no 106 cm 3 Determine the equilibrium hole concentration po A 1 10 x 10 4 cm B 2 25 x 10 5 cm C 1 10 x 10 5 cm D 7 36 x 10 6 cm E 2 25 x 10 4 cm Download Attachments 26280242 2268324 jpeg Skip Question Show Comment Report Issue Subject Electrical Engineering i Reminder If you copy content from another source you violate our policy and your account may be blocked See our warning and violations policy Select the answer A B C Explanation D E Do the options look incorrect Answer in freeform text 2 00

Pfa here I read somewhere that two not gates in pair gets cancelled Kindly elaborate The circuit a shown in the figure has output Y 1 if the inputs A and B respectively are D D A B A B 0 0 0 1 Y

b A pn junction is made of Si with intrinsic carrier density n 1 02 10 0 cm and also impurity atoms with concentrations as indicated in the figure 1 Identify the p region and the n region ii Calculate the minority carrier concentration in the p region n ND 5 10 cm iii Calculate the minority carrier N 2 10 7 cm concentration in the n region p Np5x1015 cm

A circuit and the signal applied at its input terminal V are shown in figure below Which one of the options correctly describes the output waveform V Assume all the devices used are ideal and taking P as reference potential 2V 0 2V A B C D 2V 0 2V 2V 4V P V HH C AD V

The output of the given circuit in figure shown R ww Will be zero for all time Is Half wave rectified with Positive cycle in output X Is Half wave rectified with negative cycle in output Is full wave rectified Asked by 2284648 aesl id Standard XII Stream NEET Jul 14 2021 a 5 06 PM Add your responses Type Text Type your answer here OR you can upload an attachment from the option below

In common base connection of a transistor current gain is 0 99 Current gain in common emitter connection of the transistor is 1 9 9 3 99 2 999 4 990