Boolean LogicExam Tips

Exam Tips - Logic Gates

Part of Logic GatesGCSE Computer Science

This exam tips covers Exam Tips - Logic Gates within Logic Gates for GCSE Computer Science. Revise Logic Gates in Boolean Logic for GCSE Computer Science with 15 exam-style questions and 20 flashcards. This topic appears less often, but it can still be a useful differentiator on mixed-topic papers. It is section 8 of 8 in this topic. Treat this as a marking guide for what examiners are looking for, not just a fact list.

Topic position

Section 8 of 8

Practice

15 questions

Recall

20 flashcards

Exam Tips - Logic Gates

Drawing gate symbols:

  • AND gate: Draw a D-shape (flat back, curved front)
  • OR gate: Draw a pointed shape (curved back, pointed front)
  • NOT gate: Draw a triangle with a small circle (bubble) at the output
  • The bubble ALWAYS means NOT (inversion)

Common exam mistakes to avoid:

  • Forgetting that AND requires ALL inputs to be 1 - not just one!
  • Confusing AND and OR symbols - remember AND is D-shaped, OR is pointed
  • Missing the NOT bubble - it's essential for showing inversion
  • Wrong truth table: AND has only ONE 1 (bottom row), OR has only ONE 0 (top row)

Quick truth table memory tricks:

  • AND: Think "strict gate" - only 1,1 passes through → gives 1
  • OR: Think "generous gate" - only 0,0 blocks → gives 0
  • NOT: Think "flip gate" - whatever goes in, opposite comes out

Keep building this topic

Read this section alongside the surrounding pages in Logic Gates. That gives you the full topic sequence instead of a single isolated revision point.

Practice Questions for Logic Gates

An AND gate has inputs A=1 and B=0. What is the output?

  • A. 0
  • B. 1
  • C. Always 1
  • D. Always 0
1 markfoundation

Complete the truth table for an OR gate with two inputs A and B. | A | B | Output | |---|---|--------| | 0 | 0 | | | 0 | 1 | | | 1 | 0 | | | 1 | 1 | |

3 marksstandard

Quick Recall Flashcards

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