Question

Match List - I with List - II.

List - I	List - II
A. LED B. Avalanche photo diode C. Tunnel diode D. LASER	I. Heavy doping II. Coherent Radiation III. Spontaneous Emission IV. Current Gain

• A. A-I, B-II, C-IV, D-III
• B. A-II, B-III, C-I, D-IV
• C. A-III, B-IV, C-I, D-II
• D. A-II, B-I, C-IV, D-III

Hint:

Important associations:
• LED \(\rightarrow\) Spontaneous emission
• LASER \(\rightarrow\) Coherent radiation
• Tunnel diode \(\rightarrow\) Heavy doping
• Avalanche photodiode \(\rightarrow\) Current gain

Answer 1

The Correct Option is C

Concept: This question involves matching semiconductor and optical devices with their characteristic properties.

Step 1: Matching LED. LED works on: \[ \text{Spontaneous emission} \] Thus: \[ A \rightarrow III \]

Step 2: Matching Avalanche photodiode. Avalanche photodiode provides: \[ \text{Internal current multiplication gain} \] Hence: \[ B \rightarrow IV \]

Step 3: Matching Tunnel diode. Tunnel diode is:
• extremely heavily doped,
• has very thin depletion region. Therefore: \[ C \rightarrow I \]

Step 4: Matching LASER. LASER produces: \[ \text{Coherent radiation} \] Hence: \[ D \rightarrow II \]

Step 5: Writing the final matching. Thus: \[ A-III,\;B-IV,\;C-I,\;D-II \] Hence correct option is: \[ \boxed{(3)} \]