ALU 101 Binary Number Systems 3

Question 1

What is the octal equivalent of binary 110101?

Accepted Answer

65

Answer

Grouping 110101 into 3-bit groups from right: 110 (6) and 101 (5) gives octal 65.

Question 2

How does the ALU detect an arithmetic overflow in signed binary addition?

Accepted Answer

When carry into and carry out of the sign bit differ

Answer

Overflow occurs in signed addition when the carry into the most significant bit differs from the carry out of it.

Question 3

What is the value of binary 1000 0000 in an 8-bit two's complement system?

Accepted Answer

-128

Answer

In 8-bit two's complement, 10000000 represents −128, the most negative representable value.

Question 4

Which number system uses the digits 0–7?

Accepted Answer

Octal

Answer

The octal number system (base 8) uses the digits 0 through 7.

Question 5

What is 1111 × 0010 in binary?

Accepted Answer

11110

Answer

1111 (15) × 0010 (2) = 30, which is 11110 in binary.

ALU 101 - Arithmetic Logic Unit 101 Exam Practice Test