Semiconductors Questions and Answers

36 In a circuit a diode was used and the output voltage across the diode was always 50 volts even if the input voltage fluctuated between 110 V to 90 V The diode used in the circuit was a a junction diode c zener diode b photodiode d light emitting diode

1 200 3 3 15 x 10 6 1 4 20 x 10 6 S Q 112 A sinusoidal voltage of peak value 200 volt is Q 112 200 for fa R connected to a diode and resistor R in the circuit shown so that half wave rectification occurs If the forward resistance of the diode is negligible compared to R the rms voltage across R is 100 2 KH 200 Volt Peak value Diode R 2 100 4 283 3 15 x 10 6 S 1 wwwww rate at a fer Ra 1 200 3 4 20 x 10 6 100 2 200 Volt Peak value Diode R 2 100 4 283 www f

The circuit diagram shown in the figure corresponds to B A V CC R NOR NAND OR AND Y Asked by 2284648 aesl id Standard XII Stream NEET Jul 14 2021 at 5 02 PM

ent In the case of a p n junction diode if the reverse bias is very high there is a sudden large increase in current In this case the value of reverse bias voltage is known as a Cutoff voltage c Knee voltage b Critical voltage d Zener voltage

Which of the following is TRUE for a pn diode A Its forward bias resistance does not obey Ohm s law B A Zener diode is used for rectification C A photodiode based on a pn diode works in the forward bias D A light emitting diode based on a pn diode works in the reverse bias

An intrinsic semiconducting crystal has 2x 1028 atoms per m It is doped with a very small a few ppm concentration of a pentavalent impurity If the number of electrons before doping was 2 x 10 6 per m the number of holes per m after doping is very nearly equal to A 4 1038 B 2 x 1010 C 10 4

39 Two point charges Q and 20 are fixed on the X axis at positions a and 2a from origin respectively At what positions on the axis the resultant electric field is zero a Only x 2a b Only x za c Both x 2a d Only x 3a 2

6 The output of the given circuit in figure given below Vm sin co wwwwww K a would be zero at all times b would be like a half wave rectifier with positive cycles in output c would be like a half wave rectifier with negative cycles in output d would be like that of a full wave rectifier

Solvelancer Test The correct statement for the following oxides is 1 Zinc Oxide 2 Aluminium oxide Solvelancer Test a Both are acidic b Both are basic c Both are amphoteric d 1 is acidic and 2 is basic

For the logic circuit shown the truth table is 1 3 B A 0 0 1 A 0 0 1 B 0 1 0 0 1 0 Y 1 1 1 BY 0 0 0 2 4 NCERT XII II 498 A 0 0 1 1 Y 0 0 1 B 0 1 0 1 Y 11 0 0 0 ABY 0 1 0 0 1 1 1

In the circuit shown below the Zener diode is used to regulate the voltage across the load R 500 2 For an unregulated power supply V of 12 V the voltage across the load is to be maintained at 8 V If the resistor R has a value of 100 92 the current through the Zener diode is 12 V R 100 92 www A 16 mA B 24 mA C 40 mA R 500 02

Suppose that pure silicon is doped with antimony such that one silicon atom in a billion is replaced by a Sb atom Is this an n type or p type semiconductor By what factor is the density of conduction electrons increased The intrinsic density of conduction electrons in silicon is about 10 6 m at room temperature Estimate the room temperature conductivity of this material assuming the electron and hole mobilities are the same as for the intrinsic material The conductivity of silicon at room temperature is 1 6x10 mho m By comparison the conductivity of copper is about 6x107mho m

In Fresnel diffraction if the distance between the disc and the screen is decreased the intensity of central bright spo will 1 Increase 2 Decrease 3 Remain constant 4 None of these A plane wavefront 6x10 7m falls on a slit 0 4 mm wide A convex lens of focal length 0 8m placed behind the sli

When a transverse wave travels in a medium the displacement y of a particle located at x at time t is given by y a sin bt cx where a b and c are constants A The dimension of a is the same as that of y B The SI unit of b is second C The dimensional formula of c is M L T b D The dimension of is same as of velocity

For a transistor amplifier in common emitter configuration having load impedance of 1 k hre 50 and hoe 25 the current gain is 2004 A 5 2 C 24 8 B 15 7 D 48 78 of germanium are cooled from room temperature to 77 K the 10004Y

In a common base mode of a transistor t collector current is 5 488 mA for an emit current of 5 6 mA The value of the base current amplification factor will be 2006 C 50 Le To D 51 E

3 14 is equal to a and are current gain in CB CE configuration 1 a 2 a B 3 1 The value of

Which among the following expression is incorrect for a transistor Symbols have their usual meaning 9m 9m R Av Ro

19 a A scientist given an N type rectangular sample of a silicon having n 15 x 100 m The electron and hole mobility are 0 8 and 0 4 m v s What is its resistivity before and after addition of phosphorous atoms 4 2 x 10 atoms m in rectangular sample

At room temperature pure S have equal number of electron and hole concentration of 1 5 x 1010 cm 3 Doping by a trivalent atom hole concentration increases to 4 5 x 1022 m 3 The electron concentration of the semiconductor will be 5x 10 m 3 5 x 10 2m 3 5x 10 m 3 2 5 10 m 3

A silicon diode has a threshold voltage of 0 7 V If an input voltage given by 2 sin t is supplied to a half wave rectifier circuit using this diode the rectified output has a peak value of 1 2V 2 1 4V 3 1 3V 4 0 7V

The combination of gates shown in diagram is equivalent to A B D

used as the battery charging circuit shown below Assume VB 3 V R 80 Q Vs Peak 9 6 V and cut in voltage Vy 0 3 V Calculate the peak diode current and maximum reverse bias diode voltage 5 Marks Us t Vs sin cot R ww ip HIH

a The common emitter amplifier shown in the figur is biased using a 1 mA ideal current source The approximate base current value is Vcc 5 V V B 1 R 1 kn Lol OV out B 100 1 mA

20 If A and B are inputs to a NAND gate and Y is output then choose the correct option NCERT Pg 504 1 A B Y 2 B Y 3 AL Y 4 A B

A 110 V AC supply is connected between points A and B a shown in the figure A B The potential difference Vo across the capacitor is 110 V KH 110 2 V 55 2 V Zoro hr mir

A pure Si crystal has 5 x 1028 atoms m It is doped by 1 ppm concentration of As atom The number of holes per unit volume is consider n 1 5 1016 m X NCERT Pg 477 1 4 5 x 10 m 2 4 10 m 3 3 2 10 m 4 2 25 x 1010 m 3 ash

Which of the following diode is in forward bias condition When current is flowing NCERT Pg 480 1 2 3 4 V 2 V 2V 4 2V Si Ge D Ideal D Ge W 4 7 V 202 w 422 49 2 22 6V 4 V 2 1 V

In the circuit shown in the figure the input voltage is V 20 V VBE 0 VCE 0 and 3 125 The value of lg and Ic respectively are Symbols have their usual meaning 20 V V 0 5 MQ www B 40 A 5 mA 5 A 40 mA 40 A 10 mA 4 KQ C E

The voltages at V and V of the arrangement shown in the figure will be respectively cut in voltage of diodes is 0 6 V V 6 V 6 V D 6 V 5 4 V 3 V 5 4 V 5 4 V 5 4 V wwwwww www 10 KQ D 3 V V

the diffusion flux is 6 3 x 10 10 Kg m s 2 c Distinguish between Stoichiometric and non stoichiometric defects 4 a Differentiate between the elastic anelastic and viscoelastic behavior 110 plong of diamond and how many on 111 are there 3

ong the following Resistivity of semiconductor belongs in range 10 5 Om to 106 Qm O At 0 C semiconductor behaves as conductor O Eg carbon Eg silicon O When Arsenic is doped in silicon then semiconductor becomes n type

4 In an unbiased p n junction holes diffuse from the p region to n region because a free electrons in the n region attract them b they move across the junction by the potential difference c hole concentration in p region is more as compared to n region d All the above

3 A particle is executing SHM and its velocity v is related to its position x as ax b where a and b are positive constants The frequency of oscillation of particle is 1 3 2 b 2 4 2n

and is a part of a circuit shown in figure below diode has a breakdown potential of 15 V 25V T 3kQ www 2kQ Find the current through the 3 KQ resistor 1 5 mA 2 3 33 mA 3 6 33 mA 4 3 67 mA

D In the following figure the diodes which are forward biased are 5V 10V R A 9 10V R SV 10V R B C 1 A B and D 2 C only 3 C and A 4 B and D R 5V 3

The effect of lanthanoid contraction in the lanthanoid series of elements by and large means A increase in atomic radii and decrease in ionic radii B increase in both atomic and ionic radii D decrease in both atomic and ionic radii decrease in atomic radii and increase in ionic radii

A cell of emf 4 5 V is connected to a junction diode whose barrier potential is 0 7 V If external resistance of the circuit is 190 Q then the current in the circuit is V www R 20 mA 2 mA 0 2 mA

oblem 8 An n channel JFET has IDSS 12 mA i If the pinch off voltage Vp 4 V find drain current for VGs 2 V i If the transconductance 9m at Vas 0 is 4 millimho find the pinch off voltag

A boy A is standing 3 m west and 4 m north to a boy B A starts moving along a vector a 1 51 2j with a constant speed of 2 m s for 5 s and stops Its new position vector with respect to the boy B is xi yj Find xy

Solvelancer Test Modern solar cells use multi layer silicon arrangement due to the reason that SolveLancer Test a Silicon is available in abundance b It converts IR and visible radiations both into electricity c Multilayers increases efficiency up to 87 d Silicon has low output of electricity production

1 Point at the interior of the sample within the whole volume of the sample on the surface of the sample just outside the sample J

The logic A 1 B is equivalent to A B 00

In the following circuit the equivalent resistance between A and B is 452 43 252 10V 852 1 2 3 orrect Answer 3 our Answer 1 20 S 3 10 02 16 Q 2002 www 652 1202 B 2V

2 For a given transistor B 100 Ve 0 7 V Find VCE 18V 100 2 1 13 V 3 10 V 8 6 k 4 5V BI E 2 5V 4 8 V

10 A common emitter amplifier is designed with n p n transistor 0 99 The base resistance is 1 k and load is 10 k2 The voltage gain will be 1 9900 2 99 3 9 9 4 990 11 Two radioactive sample decay constant are 15x and

Test 6 Code A 39 A zener diode having Zener voltage equal to 15 Vis used in voltage regulator circuit as shown The current through the Zener diode is 1 20 mA 20 V 50 2 5 mA

Consider the circuit shown below and determine IC Data VBB 0 66 V Vcc 5 V Rc 1k0 Use V 26 mV npn transistor Is 12 FA B 100 0 0 O 5 MA O 13 MA VBB IB 1 NB 14 Y Vcc VBE Re VRC Ic www Vc VCE VE 0 IE

44 In the combination of the following gates the output Y can be written in terms of inputs A and B as Ao BO 1 AB 3 A B 2 AB AB 4 AB AB OY

Physics 311 wk LITC n lightg built in potential Vo As a result the depletion layer width decreases and the barrier height is reduced Fig 14 13 b l The effective barrier height under forward bias is V V If the applied voltage is small the barrier potential will be reduced only slightly below the equilibrium value and only a small number of carriers in the material those that happen to be in the uppermost energy levels will possess enough energy to cross the junction So the current will be small If we increase the annlied voltage significantly the barrier height will be reduced Add your responses Type Text Type your answer here OR you can upload an attachment from the option below Attachment size should be 5MB or less Keep the format in jpg or png or pdf or doc or docx only Asked by 611642 aesl id Standard XII Stream NEET Aug 2 2021 at 9 26 PM is n limi sid Add Attachment inc br in la