Match electronic components to predominant noise types: (A) Resistance, (B) Diode, (C) Triode, (D) p–n junction — with: (1) current noise, (2) partition noise, (3) shot noise, (4) atmospheric noise, (5) Johnson (thermal) noise.

Introduction / Context:
Recognizing dominant noise mechanisms is key for low-noise design. Thermal agitation in resistors, discrete charge flow in junctions, and carrier partition in multi-electrode devices create distinct spectral behaviors that affect receivers and amplifiers across RF and audio bands.

Given Data / Assumptions:

• Resistor noise is thermal (Johnson noise).
• Diode junctions exhibit shot noise due to discrete charge carriers traversing a barrier.
• Vacuum triodes exhibit partition noise from electron stream division among electrodes.
• p–n junctions can exhibit current-related (shot/flicker) noise; here 'current noise' is the remaining classified term to pair.

Concept / Approach:
Map each device to the noise it is most classically associated with in exam syllabi: Johnson noise ↔ resistors; shot noise ↔ diodes; partition noise ↔ multi-electrode tubes; current noise ↔ semiconductor junction conduction fluctuations.

Step-by-Step Solution:

Verification / Alternative check:
Spectral traits: thermal noise ~ kTB across resistors; shot noise current ~ 2qI*B in junctions; partition noise arises where carriers split among paths (e.g., triodes).

Why Other Options Are Wrong:

• A-1, B-2, C-3, D-5: Misplaces thermal and shot noise pairings.
• A-3, B-5, C-1, D-2: Assigns shot noise to resistors, which is incorrect.
• A-3, B-5, C-2, D-1: Gives diodes thermal noise as dominant, which is not typical.

Common Pitfalls:

• Confusing thermal noise (present in any resistance) with shot noise (junctions).
• Assuming atmospheric noise originates in components; it is an external interference source.

Final Answer:
A-5, B-3, C-2, D-1