💡 Chapter 19: Electronics – Multiple Choice Questions
Prepared by Muhammad Tayyab, Subject Specialist Physics, Govt Christian High School Daska. Based on PECTAA 2026 syllabus (National Curriculum 2023).
📖 What's Inside: This chapter covers diode current flow, LED function, NOR gate output, NAND gate output, and byte size. Each MCQ is presented with the correct answer and detailed explanation as per the official PECTAA 2026 Physics curriculum. Perfect for Punjab Boards (Lahore, Gujranwala, Multan, etc.) and all BISE boards across Pakistan.
📚 Related Resources – Chapter 19: Electronics
Electronics covers semiconductor devices, diodes, LEDs, logic gates, Boolean algebra, and digital circuits.
📖 Multiple Choice Questions (PECTAA 2026)
19.1 A diode allows current to flow in:
✅ Correct Answer: (C) one direction only
A diode is like a one-way road for current allowing it to flow in only one direction and blocks in the opposite direction.
A diode is like a one-way road for current allowing it to flow in only one direction and blocks in the opposite direction.
19.2 What is the primary function of a light-emitting diode?
✅ Correct Answer: (B) To emit light when current passes in one direction
A Light-Emitting Diode (LED) is a semiconductor device that allows electric current to flow in one direction, like a typical diode, and emits light when electrons recombine with holes.
A Light-Emitting Diode (LED) is a semiconductor device that allows electric current to flow in one direction, like a typical diode, and emits light when electrons recombine with holes.
19.3 The output of a two inputs NOR gate is '1', when:
✅ Correct Answer: (C) both A and B are '0'
The output is 1 when both inputs A and B are 0, otherwise output is 0.
The output is 1 when both inputs A and B are 0, otherwise output is 0.
19.4 The output of a NAND gate is '0', when:
✅ Correct Answer: (B) both of its inputs are '1'
The output is 0 when both inputs A and B are 1, otherwise output is 1.
The output is 0 when both inputs A and B are 1, otherwise output is 1.
19.5 How many bits make up a byte in Boolean logic?
✅ Correct Answer: (D) 8
A byte is formed using eight bits, which represents data in computers.
A byte is formed using eight bits, which represents data in computers.
⚡ Key Logic Concepts – Electronics
NOR Gate: Output is 1 only when both inputs are 0.
NAND Gate: Output is 0 only when both inputs are 1.
Byte: 1 Byte = 8 bits
Diode: Allows current in one direction only.
Unit 10Thermal Physics
Unit 11Transfer of Thermal Energy
Unit 12Waves
Unit 13Sound
Unit 14Light
Unit 15Electrostatics
Unit 16Electricity
Unit 17Electromagnetism
Unit 18Electromagnetic Induction & EM Waves
Unit 19✨ Electronics
Unit 20Atomic and Nuclear Physics
Unit 21Space and Environment
📖 Complete syllabus coverage for Class 10 Physics (PECTAA 2026) – Units 10 to 21
💡 Exam Tip:
For board exams, read each question carefully and eliminate obviously wrong options. These MCQs follow the PECTAA 2026 pattern and are prepared by Subject Specialist Muhammad Tayyab.
Created by Hira Science Academy | Aligned with PECTAA 2026 Syllabus