OPERATING SYSTEM MCQS PART 13

OPERATING SYSTEM MCQS PART 13

1. The number of digits in octal system is ………
1. 8                     
2. 7          
3. 9          
4. 10
Answer : 1
Explanation:  The octal system has 8 digits 0 to 7.  

2. The access time of a word in 4 MB main memory is 100 ms. The access time of a word in a 32 kb data cache memory is 10 ns. The average data cache bit ratio is 0.95. The efficiency of memory access time is ………
1. 9.5 ns              
2. 14.5 ns           
3. 20 ns          
4. 95 ns
Answer : 2
Explanation:  Access time = 0.95 x 10 + 0.05 x 100.

3. The expression Y = pM (0, 1, 3, 4) is …………..
1. POS           
2. SOP              
3. Hybrid       
4. none of these
Answer : 1

4. An 8 bit DAC has a full scale output of 2 mA and full scale error of ± 0.5%. If input is 10000000 the range of outputs is ………….
1. 994 to 1014 μA  
2. 990 to 1020 μA   
3. 800 to 1200 μA  
4.none of the above
Answer : 1

5. Decimal 43 in hexadecimal and BCD number system is respectively……. and ……..
1. B2 and 01000011  
2. 2B and 01000011   
3.2B and 00110100
4. B2 and 01000100
Answer : 2
 
6. 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

7. 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
Explanation:  The largest negative number is 1000 0000 = -128.

8. 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 

9. The basic storage element in a digital system is ………….
1. flipflop            
2. Counter            
3. Multiplexer           
4. encoder
Answer : 1Explanation: Storing can be done only in memory and flip-flop is a memory element.

10. 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
Explanation:  In a ripple counter the effect ripples through the counter.