adder and subtractor in digital electronics

Simplified expression of half adder carry is 

• c=xy+x
• c=y+x
• c=xy+y
• c=xy

3 bits full adder contains

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

Examples of combinational ckts are

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

Nor function is dual of

• and function
• or function
• xor function
• nand function

which of the following circuits can be used as parallel to serial converter?

• Multiplexer

• Demultiplexer

• Digital counter

• Decoder

The number of inputs and outputs in a full adder are

• 2 and 1

• 2 and 2

• 3 and 2

• 3 and 3

which device has one input and many outputs

• flip flop

• multiplexer

• demultiplexer

• counter

which one of the following is a universal gate

• NAND gate

• AND gate

• OR gate

• EX-OR gate

XOR and XNOR are referred to as

• Sequential logic circuits

• Combinational logic circuits

• Basic logic gates

• Complex logic gates

which device has one input and many outputs

• flip flop

• multiplexer

• demultiplexer

• counter