DIGITAL ELECTRONICS-II MCQ SET-1

1. Number of memory chips needed to design 16 Kilo byte memory if the memory if the memory chip size is 1024×1.

(A) 64
(B) 16
(C) 128
(D) 1024

2. One nibble is equal to ______

(A) 8 bits
(B) 4 bits
(C) 6 bits
(D) 2 bits

3. IC 74139 is ______

(A) A 2-to-4 line decoder
(B) A 4-to-16 line decoder
(C) A 16-to-1 line multiplexer
(D) A 8-to-1 line multiplexer

4. Magnetic tape is coated with tiny particles of ______

(A) Ferric oxide
(B) Ferrous oxide
(C) Chromium dioxide
(D) All of the above

5. Which of the following is true for sampling theorem.

(A) Sampling frequency ≥ signal frequency
(B) Sampling frequency ≤ signal frequency
(C) Sampling frequency ≥ 2 x signal frequency
(D) Sampling frequency ≤ 2 x signal frequency

6. Which of the following is the fastest A/D converter

(A) Successive approximation type
(B) Parallel compartor type
(C) Dual slope type
(D) Counting type

7. For weighted resistor n-bit D/A converter, the resistor value of LSB is ______

(A) 2^n-1.R
(B) 2ⁿ.R
(C) 2R
(D) R

8. Pits and lands are related to ______

(A) Multivibrator
(B) CD-ROM
(C) Hard disk
(D) Clamper

9. The magnetic flux lines are used to write data to ______

(A) A Hard-disk
(B) A CD-ROM
(C) Both (a) and (b)
(D) None of these

10. Which of the following is true for PROM

(A) The data pattern is defined after fabrication
(B) The data pattern is defined during fabrication
(C) It is a sequential memory
(D) It is reprogrammable

11. The primary colours are

(A) Blue and red
(B) Red and green
(C) Blue, red and green
(D) Blue and green

12. The number of comparators required for an 8 bit parallel comparator A/D converter is :

(A) 255
(B) 240
(C) 300
(D) 250

13. A magnetic drum of 8″ diameter has 100 tracks and storage of 200 bits/inch. It storage capacity is :

(A) 502400 bits
(B) 8402 bits
(C) 1004800 bits
(D) 202900 bits

14. Counter can be used in the measurement of :

(A) Frequency
(B) Time
(C) Distance
(D) All of the above

15. The maximum speed of electronic switch can be ______ operations per second.

(A) 104
(B) 10
(C) 1000
(D) 109

16. The resolution of a 12 bit D/A converter is ______ of full scale output

(A) 1/4095
(B) 1/4000
(C) 1/3000
(D) 1/2000

17. The maximum sampling rate time T_s of a 10 KHz sinusoidal voltage for conversion to digital form is :

(A) 0.05 sec
(B) 0.05 ms
(C) 0.05 μs
(D) 0.05 ns

18. The access time of ROM using bipolar transistor is about :

(A) 1 sec.
(B) 1 m sec.
(C) 1 μ sec.
(D) 1 n sec.

19. R-2R ladder network is used for :

(A) Resolving interrupt priority
(B) Parallel to serial conversion
(C) D/A conversion
(D) A/D conversion

20. Which is known as one shot multivibrator :

(A) Astable
(B) Monostable
(C) Bistable
(D) None