DIGITAL ELECTRONICS MCQS SET 07

DIGITAL ELECTRONICS MCQS SET 07

1. An AND gate has two inputs A and B and one inhibit input 3, Output is 1 if
1. A = 1, B = 1, S = 1                  2. A = 1, B = 1, S = 0   
3. A = 1, B = 0, S = 1                   4. A = 1, B = 0, S = 0
Answer: 2

2. The greatest negative number which can be stored is 8 bit computer using 2’s complement arithmetic is ……..
1. -256     2. -128             3. -255             4. -127
Answer: 2

3. A JK flip flop has tpd= 12 ns. The largest modulus of a ripple counter using these flip flops and operating at 10 MHz is ……..
1. 16           2. 64               3. 128              4. 256
Answer: 4

4. The basic storage element in a digital system is ………….
1. flipflop       2. counter        3. multiplexer          4. encoder
Answer: 1

5. In a ripple counter,
1. whenever a flipflop sets to 1, the next higher FF toggles
2. whenever a flipflop sets to 0, the next higher FF remains unchanged
3. whenever a flipflop sets to 1, the next higher FF faces race condition
4. whenever a flipflop sets to 0, the next higher FF faces race condition
Answer: 1

6. A 12 bit ADC is used to convert analog voltage of 0 to 10 V into digital. The resolution is ……….
1. 2.44 mV       2. 24.4 mV        3. 1.2 V        4. None of these
Answer: 1

7. A full adder can be made out of …………
1. two half adders                  2. two half adders and a OR gate
3. two half adders and a NOT gate             4. three half adders
Answer: 2

8. The output of a half adder is ……….
1. Sum       2. Sum and Carry          3. Carry            4. none of these
Answer: 2