DSD - Combinational Circuits

3 bits full adder contains

• 3 combinational inputs
• 4 combinational inputs
• 6 combinational inputs
• 8 combinational inputs

Write the output expressions for the following logic gate combinations:

• (ABC) + (DE)

• (ABC)(DE)

• (ABC) X (DE)

• (ABCDE)

Which truth table is this?

• XOR
• NAND
• NOR
• NOT

Examples of combinational ckts are

• flipflops
• adders, mux, demux
• both a and b

The number of inputs and outputs in a full adder are

• 2 and 1

• 2 and 2

• 3 and 2

• 3 and 3

A magnitude comparator is defined as a digital comparator which has ____________

• Only one output terminal

• Two output terminal

• Three output terminal

• Four output terminal

What value is input B, if output Y is high when both input A and input C are high.

• Low (0)

• High (1)

• High impedance

• Short-circuit

How many Full adders are needed to design a 6 bit parallel adder?

• 7

• 3

• 6

• 4

3 bits full adder contains

• 3 combinational inputs

• 4 combinational inputs

• 6 combinational inputs

• 8 combinational inputs

In the given 4-to-1 multiplexer, if c1 = 0 and c0 = 1 then the output M is ___________

• X0

• X1

• X2

• X3