21. What logic function is produced by adding an inverter to the output of an AND gate?

A. NAND
B. NOR
C. XOR
D. OR
E. None of the above

22. Conversion of decimal number 28₁₀ to it’s octal number equivalent is

A. 32₈
B. 40₈
C. 34₈
D. 36₈
E. None of the above

23. Division of 100011₂ by 101₂ is

A. 100₂
B. 1112₂
C. 1012₂
D. 10102₂
E. None of the above

24. The NOR gate is logically equivalent to an OR gate followed by an _____

A. AND
B. XAND
C. XOR
D. inverter
E. None of the above

25. The dynamic race hazard problem occurs in

A. combinational circuits only
B. sequential circuits only
C. both combinational and sequential circuits
D. None of the combinational and sequential circuits
E. None of the above