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Signed Arithmetic MCQs

Practice Signed Arithmetic MCQs with four options, answers and explanations for focused Electronics & Telecommunication Engineering revision.

Question 1
Digital ElectronicsSigned Arithmetic

In two’s-complement signed arithmetic, adding two positive n-bit numbers produces an overflow when?

  • AThe result has sign bit 1 even though both operands have sign bit 0
  • BA carry is produced from the LSB
  • CThe result is zero
  • DThe carry-in to the LSB is 1
Report an error
Correct Answer: A. The result has sign bit 1 even though both operands have sign bit 0
Explanation: Signed overflow occurs when operands with the same sign produce a result with the opposite sign. For two positive operands, a negative-sign result indicates overflow.
Reference: Standard digital electronics: two's-complement overflow
Question 2
Digital ElectronicsSigned Arithmetic

In two’s-complement addition, overflow can be detected by XORing which two carry signals?

  • ACarry into and carry out of the sign bit
  • BCarry into bit 0 and bit 1
  • CTwo successive clock carries
  • DCarry out and borrow out
Report an error
Correct Answer: A. Carry into and carry out of the sign bit
Explanation: For two's-complement addition, overflow equals the XOR of the carry into the most significant sign bit and the carry out of that bit.
Reference: Standard digital electronics: overflow detection