# Electronics and Communication Engineering - Digital Electronics

6.

A device which converts BCD to seven segment is called

 A. encoder B. decoder C. multiplexer D. none of these

Explanation:

Decoder converts binary/BCD to alphanumeric.

7.

In 2's complement representation the number 11100101 represents the decimal number

 A. +37 B. -31 C. +27 D. -27

Explanation:

A = 11100101. Therefore A = 00011010 and A' = A + 1 = 00011011 = 16 + 8 + 2 + 1 = 27. Therefore A = -27.

8.

 A. binary states 1000 to 1111 B. binary states 0000 to 0011 C. binary states 1010 to 1111 D. binary states 1111 to higher

Explanation:

A decade counter counts from 0 to 9. It has 4 flip-flops. The states skipped are 10 to 15 or 1010 to 1111.

9.

BCD input 1000 is fed to a 7 segment display through a BCD to 7 segment decoder/driver. The segments which will lit up are

 A. a, b, d B. a, b, c C. all D. a, b, g, c, d

Explanation:

1000 equals decimal 8 Therefore all segments will lit up.

10.

A ring counter with 5 flip flops will have

 A. 5 states B. 10 states C. 32 states D. infinite states