Advanced Engineering Physics 2022 Question Paper — Government College…
The 2022 Advanced Engineering Physics previous year question paper (Government College of Engineering and Technology, Jammu), with every question and its marks.
- University: Government College of Engineering and Technology, Jammu
- Subject: Advanced Engineering Physics
- Course: APPLIED ENGG. PHYSICS
- Year: 2022
- Paper: end-term
- Duration: 180 minutes
- Total marks: 100
Instructions
- Attempt five questions in all, selecting at least two from each section.
- All questions carry equal marks.
- Use of scientific calculator is allowed.
Questions
Section-A
- Q1. (a) Explain the concept of the Poynting Vector and derive Poynting's Theorem. Discuss its physical significance. (b) Show that $\vec{\nabla} r^n = n r^{n-2} \cdot \vec{r}$, where $\vec{r} = x\hat{i} + y\hat{j} + z\hat{k}$. [20 marks]
- Q2. (a) Explain the construction, working principle, and energy level diagram of a He-Ne laser. Discuss the role of helium and neon atoms in achieving population inversion. Also describe its output characteristics and important applications. (b) A ruby laser emits a $0.05\text{ J}$ pulse of wavelength $694\text{ nm}$. Calculate the minimum number of $\text{Cr}^{3+}$ ions required in the ruby laser. [20 marks]
- Q3. (a) A particle of mass $m$ is confined in a one-dimensional infinite potential box of length $L$. Derive the allowed energy levels and the corresponding normalized wave functions. (b) In Compton experiment, the wavelength of X-ray radiation scattered at an angle of $45^{\circ}$ is $0.022\text{ \AA}$. Calculate the wavelength of the incident X-ray. [20 marks]
- Q4. (a) Derive the time-independent Schrödinger equation and explain the concepts of operators, eigenvalues, and eigenfunctions in quantum mechanics. Also derive the expressions for the energy operator and the linear momentum operator. (b) Normalize the wave function $\Psi(x) = A\,e^{ikx}$ over the region $-a \le x \le a$. [20 marks]
Section-B
- Q5. (a) Define Hall effect. Explain Hall effect in semiconductor and derive an expression for Hall voltage and Hall coefficient. Mention its applications. (b) Find the conductivity of $n$-type Ge at room temperature, assuming one donor atom in each $10^8$ atoms. The density of Ge is $5.32 \times 10^3\text{ kg/m}^3$ and the atomic weight is $72.6\text{ kg/k-mol}$. Comment on result [$e = 1.6 \times 10^{-19}\text{ C}$, $\mu_e = 0.38\text{ m}^2\text{/V-s}$, $\mu_h = 0.18\text{ m}^2\text{/V-s}$]. [20 marks]
- Q6. (a) Explain drift and diffusion currents in semiconductors and derive their governing equations. Also state and derive the Einstein relation and discuss its significance in the operation of a PN junction. (b) Calculate the value of Hall voltage across the width of a semiconductor specimen from the following data : Width of specimen = $0.1\text{ m}$, thickness of the specimen = $0.01\text{ m}$, field applied perpendicular to width and length = $0.6\text{ T}$, current flowing lenthwise = $10\text{ mA}$, Hall coefficient = $3.8 \times 10^{-4}\text{ m}^3\text{/C}$. [20 marks]
- Q7. (a) Discuss polarized and unpolarized light. Explain the working principle of Nicol prism as a polarizer and analyser. (b) If the radius of 10th and 12th Newton's rings are $0.2\text{ cm}$ and $0.3\text{ cm}$ respectively and the plano-convex lens is of focal length $90\text{ cm}$. Calculate the wavelength of the light. [20 marks]
- Q8. (a) Explain propagation of light through an optical fibre. Derive an expression for critical angle of propagation. (b) A glass fibre is made with core glass of refractive index $1.5$ and the cladding is doped to give a fractional index difference of $0.0005$. Find : (a) cladding index, and (b) numerical aperture. [20 marks]