Question

Match List - I with List - II (Semiconductor devices).

List - I	List - II (Characteristics)
A. BJT B. MOS capacitor C. Laser Diode D. JFET	I. Population Inversion II. Pinch-off Voltage III. Early Effect IV. Flat-band Voltage

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

Hint:

Important associations:
• BJT \(\rightarrow\) Early Effect
• MOS Capacitor \(\rightarrow\) Flat-band Voltage
• Laser Diode \(\rightarrow\) Population Inversion
• JFET \(\rightarrow\) Pinch-off Voltage

Answer 1

The Correct Option is C

Concept: Different semiconductor devices are associated with specific physical phenomena and operating characteristics. To solve matching questions correctly, we must identify the most important characteristic associated with each device.

Step 1: Matching BJT with its characteristic. For a Bipolar Junction Transistor (BJT), one important phenomenon is: \[ \text{Early Effect} \] Early effect refers to:
• variation in effective base width,
• change in collector current with collector voltage,
• finite output resistance of BJT. Thus: \[ A \rightarrow III \]

Step 2: Matching MOS capacitor with its characteristic. A MOS capacitor is associated with: \[ \text{Flat-band Voltage} \] Flat-band voltage is the voltage at which:
• energy bands become flat,
• there is no band bending in semiconductor,
• electric field inside semiconductor becomes zero. Hence: \[ B \rightarrow IV \]

Step 3: Matching Laser diode with its characteristic. Laser diode operation depends on: \[ \text{Population Inversion} \] Population inversion means:
• more electrons occupy excited state than ground state,
• stimulated emission becomes dominant,
• coherent laser light is produced. Therefore: \[ C \rightarrow I \]

Step 4: Matching JFET with its characteristic. JFET operation is governed by: \[ \text{Pinch-off Voltage} \] Pinch-off voltage is the voltage at which:
• conducting channel becomes constricted,
• drain current becomes almost constant. Thus: \[ D \rightarrow II \]

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