Combinational Logic and Sequential Circuits

Question 1

T/F: A Full Adder can be used to add multi-bit binary numbers in a ripple-carry adder?

Answer 1

True

Question 2

T/F: Full Adder can directly add three multi-binary bit numbers at once?

Answer 2

False, they can only add one bit binary numbers at once

Question 3

T/F: A Full Adder can be built using two Half Adders and an OR gate

Answer 3

True (https://www.researchgate.net/publication/349757086/figure/fig1/AS:997506271948808@1614835436421/Illustration-of-a-the-full-adder-circuit-consisting-of-two-half-adders-and-an-OR-logic.png)

Question 4

T/F: A Full Adder has three inputs: two operands and one carry-in?

Answer 4

True

Question 5

How can a Full Adder be converted into a Subtractor by modifying its inputs?

Answer 5

By inverting the second input B by using a NOT gate and set Carry-in to 1

Question 6

What is the bit width of the selection signal needed for an 8-to-1 multiplexer?

Answer 6

3

Question 7

How many ‘AND’ gates does a 3-to-8 Line decoder have?

Answer 7

8 ‘AND’ gates

Question 8

How many 2-to-4 decoders are required to design a 3-to-8 line decoder?

Answer 8

Three 2-to-4 decoders