Combinational Circuits

Question 51

The circuit shown in the given figure is a

• full adder
• full subtracter
• shift register
• decade counter

Question 52

When two numbers are added in excess-3 code and the sum is less than 9, then in order to get the correct answer it is necessary to

• subtract 0011 from the sum
• add 0011 to the sum
• subtract 0110 from the sum
• add 0110 to the sum

Question 53

The BCD adder to add two decimal digits needs minimum of

• 6 full adders and 2 half adders
• 5 full adders and 3 half adders
• 4 full adders and 3 half adders
• 5 full adders and 2 half adders

Question 54

The Excess-3 decimal code is a self-complementing code because (1)The binary sum of a code and its 9’s complement is equal to 9. (2)It is a weighted code. (3)Complement can be generated by inverting each bit pattern. (4)The binary sum of a code and its 10’s complement is equal to 9.

• (1)
• (2) and (3)
• (1) and (3)
• All are correct.

Question 55

Match the terms in List - I with the options given in List - II :

codes:

List - I	List - II
(a)Decoder	(i)1 line to 2n lines
(b)Multiplexer	(ii)n lines to 2n lines
(c)De multiplexer	(iii)2n lines to 1 line
	(iv)2n lines to 2n - 1 lines

	(a)	(b)	(c)
(1)	(ii)	(i)	(iii)
(2)	(ii)	(iii)	(i)
(3)	(ii)	(i)	(iv)
(4)	(iv)	(ii)	(i)

• (1)
• (2)
• (3)
• (4)