Electronic Systems: Transistors, Sensors & Circuits is one of 9 topics in the Grade 9 Technology CAPS syllabus, covered across 3 lessons on Study Vault. Below are real practice questions from this topic with full worked answers.
Sample practice questions
Easy
1. Which type of transistor is used at Grade 9 level?
NPN-type only
PNP-type only
Both NPN and PNP equally
Neither type is used at Grade 9 level
Answer: NPN-type only — Only the NPN-type transistor is used at Grade 9 level.
Easy
2. What are the two main jobs a transistor can perform in a circuit?
Acting as a switch, and amplifying a small current
Storing light energy, and generating sound
Measuring voltage, and measuring resistance
Only ever acting as a switch, with no other function
Answer: Acting as a switch, and amplifying a small current — A transistor can act as a switch (a small base current allowing a much larger collector-emitter current to flow) and can amplify a small current into a larger one.
Medium
3. Name the transistor connection into which a small current flows to "open the gate," allowing a much larger current to flow elsewhere in the transistor.
Answer: base — A small current flowing into the base "opens the gate," allowing a much larger current to flow between the collector and the emitter.
