# Electronics and Communication Engineering - Digital Electronics

11.

BCD number 1100111 = __________ 10

 A. 66 B. 67 C. 68 D. 69

Explanation:

0110 = 6 and 0111 = 7 Hence 67.

12.

The K-map for a Boolean function is shown in figure. The number of essential prime implicants for this function is

 A. 4 B. 5 C. 6 D. 8

Explanation:

Essential Prime implicates = 4.

13.

When microprocessor processes both positive and negative numbers, the representation used is

 A. l's complement B. 2's complement C. signed binary D. any of the above

Explanation:

2's complement representation requires simple electronic circuitry.

14.

An AND gate has four inputs. One of the inputs is low and other inputs are high. The output

 A. is low B. is high C. is alternately low and high D. may be high or low depending on relative magnitudes of inputs

Explanation:

In AND gate all inputs must be high to give high output.

15.

In the given figure, the flip flop is

 A. negative edge triggered B. positive edge triggered C. level triggered D. either (a) or (c)