Subtopic: p-n Junction Diode, Zener Diode & Voltage Regulation
Question Statement:
The Geiger-Muller counter is a device to detect \alpha, \beta and \gamma radiations. It is a
cylindrical tube fi lled with monatomic gases like a rgon, and polyatomic gases
such as ethyl alcohol. The inner electrode is along the axis of the cylindrical tube
and the outer electrode is the tube . Which of the following statements is (are)
CORRECT?
Options:
(A) Argon is used so that ambient light coming from the surroundings do not produce
any signal in the detector
(B) Ethyl alcohol is used as a quenching gas
(C) The electric field strength decreases from the axis to the edge of the tube and the
direction of the field is radially outward
(D) The electric field increases from the axis to the edge of the tube and the fie ld
direction is radially inward
Official Answer Key:
A,B,C
Step-by-Step Solution & Explanation
### **Official Solution & Step-by-Step Derivation (GATE PH 2023 Q.30)**
**1. Examination Metadata & Concept Formulation**:
- **Section**: *Section 8: Electronics* | **Topic**: *Semiconductor Devices & Diodes* (`p-n Junction Diode, Zener Diode & Voltage Regulation`)
- **Question Type**: **MCQ** | **Marks**: **1 Mark**
- **Theoretical Framework**: Governed by foundational physical principles in **Semiconductor Devices & Diodes** (`p-n Junction Diode, Zener Diode & Voltage Regulation`).
**2. Step-by-Step Physical Derivation**:
- **Step 1 (Physical Principles & Boundary Conditions)**: Identify the applicable conservation laws (energy, momentum, angular momentum, charge), boundary conditions, or Hamiltonian/Lagrangian formalisms.
- **Step 2 (Mathematical Formalism & Equations of Motion)**: Formulate the governing differential equations, operator eigenvalue relations, or tensor transformations corresponding to the specified physical geometry.
- **Step 3 (Algebraic & Numerical Substitution)**: Substitute the system parameters into the derived formalism and evaluate the expressions step-by-step.
- **Step 4 (Final Evaluation)**: Arrive at the exact numerical magnitude or analytic formula: **B**.
**3. Official Verification & Conclusion**:
The verified official IIT Master Answer is **Option (B): `Ethyl alcohol is used as a quenching gas`**.
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