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Q1. | In a junction transistor, the collector cut-off current 'I_{CB0}' reduces considerably by doping the |

A. | emitter with high level of impurity [Correct Answer] |

B. | emitter with low level of impurity [Wrong Answer] |

C. | collector with high level of impurity [Wrong Answer] |

D. | collector with low level of impurity [Wrong Answer] |

View Answer
Explanation:-
Answer : ADiscuss it below :!! OOPS Login [Click here] is required to post your answer/resultHelp other students, write article, leave your comments |

**Also Read Similar Questions Below :**

⇒ To produce

*p*type semiconductor we add

acceptor atoms

donor atoms

pentavalent impurity

trivalent impurity

⇒ If the intrinsic resistivity at 300°K is 0.37

*ohm-m*and the electron and hole mobilities at 300°K are 0.28 and 0.15

*m*

^{2}/volt-sec, then the intrinsic carrier concentration of Germanium is __________ .

2.92 x 10

^{19}/

*m*

^{3}

2.92 x 10

^{-19}/

*m*

^{3}

1.92 x 10

^{19}/

*m*

^{3}

3.92 x 10

^{19}/

*m*

^{3}

⇒

**Assertion (A):** At a temperature of 1000 K, thermionic emission current is about 0.1 A/cm^{2} of surface.

**Reason (R):** Thermionic emission current is given by I_{th} = SA_{0} *T*^{2} *e*^{-Ew/kT}.

Both A and R are true and R is correct explanation of A

Both A and R are true but R is not correct explanation of A

A is true but R is false

A is false but R is true

⇒ The passband of the tuned circuits of a radio receiver should be equal to

20 kHz

455 kHz

1455 kHz

more than 455 kHz

⇒ Which of the following element does not have three valence electrons?

Boron

Aluminium

Gallium

Phosphorus

⇒ A half wave diode rectifier and full wave diode bridge rectifier both have an input frequency of 50 Hz. The frequencies of outputs respectively are

100 Hz and 50 Hz

50 Hz and 100 Hz

100 Hz each

50 Hz each

⇒ If V

_{dc1}is the dc output voltage in half wave controlled rectifier circuit feeding resistive load and V

_{dc2}is the dc output voltage in full wave controlled rectifier circuit (M - 2 connection) feeding resistive load, then

V

_{dc1}= 0.5 V

_{dc2}for all values of firing angle

V

_{dc1}= V

_{dc2}for all values of firing angle

V

_{dc1}≤ 0.5 V

_{dc2}for all values of firing angle

V

_{dc1}≥ 0.5 V

_{dc2}for all values of firing angle

⇒ An 8085 microprocessor based system uses a 4 k x 8 bit RAM whose address in AAOOH. The address of the last byte in this RAM is

OFFFH

1000H

B9FFH

BA00H

⇒ Which multivibrator can be used as a clock timer?

Astable multivibrator

Bistable multivibrator

Any of the above

None of the above

⇒ In an op-amp a virtual ground is a ground for

voltage only

current only

both voltage and current

neither voltage nor current

⇒ The bandwidth required for amplitude modulation is

half the frequency of modulating signal

equal to the frequency of modulating signal

twice the frequency of modulating signal

four times the frequency of modulating signal

⇒ The directive gain of λ/2 resonant wire is 1.64.

TRUE

FALSE

⇒ A constant

*k*low pass filter has

*f*

_{c}= 500 Hz. At

*f*= 1000 Hz, the attenuation is

zero

infinity

may be zero or infinity

more than zero but less than infinity

⇒ For an RC admittance function Y,

Y(∞) < Y(0)

Y(0) < Y(∞)

Y (∞) may be lesser or greater than Y(0)

Y(∞) = Y(0)

⇒ An unmodulated voltage 10

*V*effective is applied to a dioxide detector in which load resistance is 4 x 10

^{-5}ohms. A micrometer shows that the rectified DC current in this resistance is 30

*A*. The efficiency of detection is

0.34

0.555

0.688

0.847

⇒ The ionosphere plays a significant role in radio wave propagation at

high frequency

ultra-high frequencies

microwave frequency

optical frequencies

⇒ Octal 16 is equal to decimal

13

14

15

16

⇒ A single phase half wave converter is feeding a resistive load. Output dc power is P

_{dc}and total power delivered to load is P

_{ac}then

P

_{dc}= P

_{ac}for all values of firing angles

P

_{dc}= P

_{ac}if firing angle is less than 180°

P

_{dc}< P

_{ac}for all values of firing angles

P

_{dc}< P

_{ac}if firing angle is less than 180°

⇒ L[

*c*

_{1}

*f*

_{1}(

*t*) +

*c*

_{2}

*f*

_{2}(

*t*)] =

*c*

_{1}F

_{1}(

*j*ω) +

*c*

_{2}F

_{2}(

*j*ω)

*c*

_{1}F

_{1}(

*j*ω) -

*c*

_{2}F

_{2}(

*j*ω)

*c*

_{1}F

_{1}(

*j*ω) +

*c*

_{2}F

_{2}(

*j*ω) +

*c*

_{1}

*c*

_{2}

*c*

_{1}F

_{1}(

*j*ω) +

*c*

_{2}F

_{2}(

*j*ω) +

*c*

_{1}/

*c*

_{2}

⇒ Two coils X of 1000 turns and Y of 2000 turns are placed such that 60% of the flux produced by coil X links coil Y. A current of 1 A in coil X produces 0.1 wb flux. The mutual inductance between coils is

0.12 H

0.08 H

0.06 H

0.04 H

⇒ A LASCR has

4 semiconductor layers and 3 junctions

3 semiconductor layers and 2 junctions

2 semiconductor layers and 2 junctions

any of these depending on the rating

⇒ Which op-amp circuit uses a diode as one of the circuit components?

Integrating amplifier

Differentiating amplifier

Logarithmic amplifier

Summing amplifier

⇒ When iron rod is magnetised by the flowing through its coil, the polarities of its different points wil

Pole A is N-pole, B is S-pole and C is neutral

A is N, B and C is S

A is N, C is S

A is S, C is neutral, B is N

⇒ If 100 V is the peak voltage across the secondary of the transformer in a half-wave rectifier (without any filter circuit), then the maximum voltage on the reverse-biased diode is

200 V

141.4 V

100 V

86 V

⇒ If VSWR is infinite, the transmission line is terminated in

short circuit

complex impedance

open circuit

either (a) or (c)

⇒ Consider a system whose input

*x*and output

*y*are related by the equa

Causal, LP

BIBO, LTI

BIBO, Causal, LTI

LP, LTI

⇒ The Hilbert transform of cos ω

_{1}

*t*+ sin ω

_{2}

*t*is

sin ω

_{1}

*t*+ cos ω

_{2}

*t*

sin ω

_{1}

*t*- cos ω

_{2}

*t*

cos ω

_{1}

*t*- cos ω

_{2}

*t*

sin ω

_{1}

*t*+ sin ω

_{2}

*t*

⇒ The correct hierarchy of operations for the operators & &, = = , = , * is

& & , = = , = , *

* , = = , & & , =

* , & & , = = , =

= , & & , = = , *

⇒ With negative feedback the closed loop gain is always less than open loop gain.

TRUE

FALSE

⇒ A voltage wave is

*i*= 100 sin (ω

*t*). Its average value calculated over one half cycle is

zero

70.72 V

63.70 V

none of the above