📣 Paper 3 has been removed from NET from 2018 (Notification)- now paper 2 and 3 syllabus is included in paper 2. Practice both paper 2 and 3 from past papers.

# NTA NET December 2018 Electronic Science Part 1

Online Paper 1 complete video lectures with Dr. Manishika Jain. Join now!

Detailed solutions to these questions are available at doorsteptutor. com

Q-1 The plot of modulating index versus carrier amplitude yields a

Options:-

1. Vertical line
2. Hyperbola
3. Horizontal line
4. Parabola

Q-2 The positive RF peaks of an amplitude modulated voltage rise to a maximum value of 12 V and drop to a minimum value of 4 V. the modulating index () assuming single tone modulation is

Options:-

1. 3

Q-3 The junction capacitance of a thyristor in the state of reverse blocking is 20 pF. For a charging current of 5 mA, the value if capability of thyristor to make it ON is

Options:-

1. 225 V/µs
2. 200 V/µs
3. 500 V/µs
4. 250 V/µs

Q-4 An exact position of Fermi level in an n-type semiconductor is

Options:-

Q-5 Two machine codes 3EH and 32H are stored in memory locations 2000H and 2001H respectively. The first machine code (3EH) represents the opcode to load a data byte in the accumulator, and the second code (32H) represents the data byte to be loaded in the accumulator. The time required executing the Opcode Fetch and the memory Read Cycles and the entire instruction cycle is, (if clock frequency is 2 MHz) .

Options:-

1. 3.5 µs
2. 3.5 ms
3. 0.5 µs
4. 1.5 µs

Q-6 What is the output of the statement?

int x, y;

scanf ( “% d” , x) ;

y = (x > 5? 3: 4) ;

Options:-

1. This statement will store 3 in y if x is greater than 5, otherwise it will store 4 in y.
2. This statement will store 4 in y if x is smaller than 5, otherwise it will store 3 in y.
3. This statement will store 3 in y if x is smaller than 5, otherwise it will store 4 in y.
4. This statement will store 4 in y if x is greater than 5, otherwise it will store 3 in y.

Q-7 Which of the following is not correct in respect of a phase-lead compensation network?

Options:-

1. It is used when phase decreases rapidly near crossover frequency
2. It is used when fast transient response is required
3. It increases system bandwidth
4. It increases gain at higher frequencies

Q-8 For equation of continuity which of the following is true (for steady state currents) ?

Options:-

Q-9 Consider the logical circuit shown in the figure below, the function , and f (in canonical sum of products form in decimal notation) are

the function is

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Q-10 if density of states in conduction band and density of states in valence band are not equal, then the Fermi level in intrinsic semiconductor is

Options:-

Q-11 if ‘α’ is the duty cycle, the output of the following circuit is given by

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Q-12 A Hall-effect element is used for the measurement of magnetic field of 0.8 . The thickness of the element is 2.5 mm and is of bismuth material. If the current passed through the element is 4A, then the Hall emf developed will be: (Hall coefficient is )

Options:-

Q-13 In a single mode fiber, the power received is 1 % that of the transmitted power. The attenuation of a single mode fiber is of the order of

Options:-

1. -20 dBm
2. -2 dBm
3. -30 dBm
4. -10 dBm

Q-14 If and , then will be

Options:-

Q-15 A transistor with is to be used in the emitter feedback bias configuration. If , the stability factor is

Options:-

1. 32.5
2. 65
3. 1
4. 1.57

Q-16 RAL is an example of

Options:-

Q-17 the Fourier transform of the signal , a > 0 will be

Options:-

Q-18 In an n-p-n transistor operating in saturated mode, the output voltage is

Options:-

1. Between and
2. Greater than
3. Equal to
4. Less than

Q-19 the output of the program

main ()

{

int i = 1;

{

{

{

printf ( “⧵n % d” , i) ;

}

printf ( “% d” , i) ;

}

printf ( “% d” , i) ;

}

}

is

Options:-

1. 3
2. 111
3. 1
4. 11

Q-20 Which of the following functions implements the Karnaugh map shown below? ‘X’ being don՚t care condition.

 AB/CD 00 01 11 10 00 0 0 1 0 01 X X 1 X 11 0 1 1 0 10 0 1 1 0

Options:-