Question 1 (20 marks) (a) By assuming 8-bit word length, express the decimal number -38 in ) Signed-magnitude One's complement Two's complement. [2 marks) 2 marks] 2 marks] (b) Subtract 1421o from 4610 Using 16-bit 2's complement form addition and state the [5 marks] answer in hexadecinal. (c) Discuss the drawback of 1's complement representation compared to 2's 4 marksl (d) Explain why NOR gate is an universal gate for for AND, OR and NOT gates. [5 marks] Question 2 (20 marks) Fig. 1 shows a half-adder with thetuth-table given as below Fig. 1 (a) List the input and output bits of this half-edder (b) Briefly explain the operation of a half-adder (c) Write the Boolean equations for the Sum Bit and the Carry Output bit. 4 marks) (d) Construct a half-adder using combination of AND and XOR gates. (e Modify the circuit in (d) into a full adder circuit [4 marks [3 marks] 4 marks] 5 marks]