Binary Number - 2 | Conversion - Electrical4u

 OCTA NUMBER SYSTEM 

The octa number system is most popular number system in digital circuit . the octa number system used digits 0,1,2,3,4,5,6,7 to represent any number . It is called Radix 8 or Base 8 .For converting an octa number into decimal we multiplying it with increasing power of  8 ,  moving from right to left .

for example , octa number 17 and 153 are written in decimal as 15 to 107 respectively.

( 17 ) base 8 = ( 15 ) base 10 = ( 1 × 8¹ + 7 × 8⁰ ) = 8 + 7 = 15

(153) base 8 = (107) base 10 = ( 1 × 8² + 5 × 8¹ + 3 × 8⁰ ) = 107

MCQ Question Based On Basic Digital electronics 

Q1. What is the correct decimal number of the binary digits of  '0100' ?

a) 1

b) 2

c) 3

d) 4 ✔️

Q2. Group of four bits is called a 

a) byte 

b) nibble ✔️

c) bit 

d) none of above 

Q3. Hexadecimal number have radix / base is 

a) 10

b) 2

c) 16 ✔️

d) 8

Q4. What  will be the output of the operations 1 + 1?

a) sum = 0 carry = 0

b) sum = 0 carry = 1 ✔️

c) sum = 1 carry = 0

d) sum = 1 carry = 1

Q5. What will be obtained from the addition of 1100 and 0001?

a) 1001

b) 1101 ✔️

c) 1000

d) 0111

Q6. Identify the gate whose truth table is given 

input  = 0 , 1

output  = 0 , 1

a) AND 

b) OR ✔️

c) NOT 

d) NAND

Q7. The logical circuit has two inputs . following observation was drawn from the circuit 

1. It output was "high" whenever both inputs were different 

2.  It output was "Low" whenever both inputs were Same

Which is the logical circuit could it be 

a) EX-OR ✔️

b) NOR 

c) NAND 

d) EX-NOR

Q8. Which of the following is a combinational circuit .

a) AND 

b) OR 

c) NOT 

d) NAND ✔️

Q9. Expression for Carry in a full adder is ( input A,B,C)

a) AB  BC CA

b) AB + BC + CA ✔️

c) AB AC BC 

d) ( AB + AC ) BC

Q10. Name of Basic GATE ?

Ans - AND . OR , NOT ✔️

Also Read - Binary Number - 1 | Conversion