📣 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 UGC Electronic Science Higher Questions KC Past Year 2013 Part 2

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Q-16. The value of Numerical Aperture in optical fibre is

(1) Greater than 1

(2) Less than 1

(3) Equal to 1

(4) Equal to

Q-17 The Refractive Index of core in optical fibre should be

(1) Smaller than R. I. of cladding

(2) greater than R. I. of cladding

(3) Equal to R. I. of cladding

(4) Equal to air

Q-18 SCR turns off from conducting state to blocking state on

(1) Reducing gate current

(2) Reversing gate current

(3) Reducing anode current below holding current value

(4) Applying ac to the gate

Q-19. The balanced modulator essentially is

Options:-

(1) An oscillator

(2) A mixer

(3) A product modulator

(4) An amplifier

Q-20. Which semiconductor device acts like a diode and two resistors?

(1) UJT

(2) SCR

(3) Diac

(4) Triac

Q-21. Which type of analogue-to-digital converter is often used in digital voltmeter?

(1) Single slope A/D converter

(2) Dual slope A/D converter

(3) Successive approximation method

(4) Flash converter

Q-22. Which of the following logic family is fastest of all?

(1) TTL

(2) RTL

(3) DCTL

(4) ECL

Q-23 Photoconductive devices are made of

(1) Radioactive materials

(2) Highly conductive materials

(3) Semiconductor materials

(4) Highly insulating materials

Q-24 The unit of mobility of semiconductor is

(1)

(2)

(3)

(4)

Q-25 The figure of merit of logic family is given by

(1) Gain bandwidth product

(2) (Propagation delay time) (power dissipation)

(3) (Fan out) (propagation delay time)

(4) (Noise margin) (power dissipation)

Q-26 In an 8085 microprocessor, the resistor which holds address of the next instruction to be fetched is

(1) Accumulator

(2) Program counter

(3) Stack pointer

(4) Instructor Register

Q-27. If a carrier modulated by a digital bit stream had one of the possible phases of 0,90, 180 and 270 degrees then modulation is called

(1) BPSK

(2) FSK

(3) QPSK

(4) QAM

Q-28. The logic gate normally used to get the carry bit in a half adder is

(1) AND

(2) EX-OR

(3) NOT

(4) OR

Q-29 A counter in which all the flip-flops receive the clock pulse at the same time is known as

(1) Ripple counter

(2) Synchronous counter

(3) Clocked counter

(4) Asynchronous counter