Grade 12 Physics Electronics Test

Read each question carefully and choose or type the best answer based on your knowledge of Electronics. Complete all sections by selecting options, filling in answers, and matching correctly before submitting for automatic marking.

GRADE 12 PHYSICS: ELECTRONICS (PNG)

Part A: Multiple Choice (10 Questions)

1. What is the process called when atoms share electrons to form a bond?

• A. Ionic bonding
• B. Covalent bonding
• C. Metallic bonding
• D. Hydrogen bonding

2. Which material is most commonly used as a semiconductor in solid-state devices?

• A. Silicon
• B. Copper
• C. Aluminum
• D. Iron

3. A diode allows current to flow freely in which condition?

• A. Reverse bias
• B. No bias
• C. Forward bias
• D. Zero bias

4. What is the terminal of a transistor that controls the flow of current?

• A. Collector
• B. Emitter
• C. Gate
• D. Base

5. Adding impurities to a semiconductor to increase conductivity is called:

• A. Rectification
• B. Doping
• C. Amplification
• D. Switching

6. Which application commonly uses a diode?

• A. Converting AC to DC
• B. Amplifying sound
• C. Storing energy
• D. Generating voltage

7. A transistor can function as a:

• A. Switch only
• B. Amplifier only
• C. Switch and amplifier
• D. Rectifier only

8. In an ionic bond, atoms interact by:

• A. Sharing protons
• B. Transferring electrons
• C. Sharing neutrons
• D. Exchanging nuclei

9. Which property of transistors makes them essential in computers?

• A. High power consumption
• B. Large physical size
• C. Mechanical movement
• D. Fast switching speed

10. The emitter region in a transistor is typically:

• A. Lightly doped
• B. Undoped
• C. Heavily doped
• D. Insulating

Part B: One Word / Short Answer (10 Questions)

11. The process of adding impurities to a semiconductor to change its electrical properties.

12. The boundary between p-type and n-type semiconductor material in a diode.

13. The condition that allows a diode to conduct current easily.

14. A circuit that uses a transistor to increase the strength of a signal.

15. The transistor terminal that controls the collector-emitter current.

16. A material whose conductivity lies between that of a conductor and an insulator.

17. A device that converts alternating current (AC) to direct current (DC).

18. A three-terminal solid-state device used for switching and amplification.

19. The negatively charged particles that move to create electric current.

20. The transistor terminal that collects charge carriers from the base region.

Part C: Matching (10 Questions)

21. Diode

Choose Allows current in one direction Amplifies signals

22. Transistor (BJT)

Choose Two-terminal rectifier Three-terminal amplifier

23. p-type semiconductor

Choose Majority carriers are holes Majority carriers are electrons

24. n-type semiconductor

Choose Majority carriers are holes Majority carriers are electrons

25. Reverse bias (diode)

Choose High resistance, blocks current Low resistance, conducts current

26. Forward bias (diode)

Choose High impedance Low impedance, conducts

27. Emitter (transistor)

Choose Heavily doped, emits charge carriers Lightly doped, controls current

28. Base (transistor)

Choose Collects majority carriers Thin layer, modulates current flow

29. Collector (transistor)

Choose Collects carriers from the base Injects carriers into the base

30. Solid-state device

Choose Uses moving mechanical parts Uses semiconductor materials

Part D: True or False (10 Questions)

31. Silicon is the most widely used semiconductor material.

• True
• False

32. A transistor has only two terminals.

• True
• False

33. Diodes are used in rectifier circuits to convert AC to DC.

• True
• False

34. In a covalent bond, electrons are transferred from one atom to another.

• True
• False

35. A transistor can act as a switch in digital electronic circuits.

• True
• False

36. The base of a transistor is more heavily doped than the emitter.

• True
• False

37. Semiconductors have conductivity between that of conductors and insulators.

• True
• False

38. The collector-emitter current in a transistor is controlled by the base current.

• True
• False

39. In an n-type semiconductor, holes are the majority charge carriers.

• True
• False

40. A diode conducts equally well in both forward and reverse bias.

• True
• False

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For Grade 11 and 12 Physics students in Papua New Guinea, mastering electronics is an essential step toward understanding how modern technology works and preparing for future careers. Electronics helps students apply important Physics concepts such as electricity, current, voltage, resistance, semiconductors, and circuits to real-world devices including mobile phones, computers, medical equipment, communication systems, solar power installations, and industrial machinery. As Papua New Guinea continues to develop its telecommunications, mining, energy, manufacturing, and infrastructure sectors, there is growing demand for people with practical electronics knowledge. A strong foundation in electronics also prepares students for further studies in electrical engineering, electronics engineering, mechatronics, robotics, telecommunications, computer engineering, renewable energy, instrumentation, and technical trades. By mastering electronics at the secondary school level, students develop valuable problem-solving, troubleshooting, and critical-thinking skills that will help them succeed in higher education and contribute to the country's technological and economic development.