PH3151 Engineering Physics Important Questions 2025

PH3151 Engineering Physics Important Questions 2025

The most important PH3151 Engineering Physics 2-mark and 16-mark questions were curated specifically for Anna University Regulations 2021. These key questions are essential for 1st Semester Engineering Physics exams for the 2024-2025 academic year.

Download the PH3151 Engineering Physics Important Questions PDF and start preparing for your 1st semester Anna University examination. These notes are made by referring to the previous year’s question papers of Anna University to help 1st year engineering students focus on the most frequently asked questions in PH3151 Engineering Physics exams.

Anna University Exam Time Table for 1st Year 2025

Anna University has officially announced the exam timetables for the non-autonomous college. Here is the Anna University UG timetable for 1st-year students under regulation 2021. The timetable for the first year is common for all departments. The exam starts in the second week of February in the year 2025 and ends in the last week of February of the year 2025.

Subject CodeSubject NameExam DateSession
GE3152Heritage of Tamil12-FEB-25FN
CY3151Engineering Chemistry17-FEB-25FN
PH3151Engineering Physics19-FEB-25FN
HS3152Professional English-121-FEB-25FN
MA3151Matrices and Calculus22-FEB-25FN
GE3151Problem-Solving Using Python Programming24-FEB-25FN
Anna University 1st Semester Time Table 2025

Engineering Physics PH3151 Previous Year Questions

PH3151 Engineering Physics previous year questions banks for Anna University (AU) regulation 2021. Here, we have given all the PH3151 Engineering Physics previous year’s question banks for Anna University 2021 regulations. You can download the Anna University (AU) regulation 2021 PH3151 Engineering Physics previous year questions for 1st semester as a PDF.

  • PH3151 Engineering Physics Jan 2022 Question Paper-  Click Here
  • PH3151 Engineering Physics April/May 2022 Question Paper-  Click Here
  • PH3151 Engineering Physics Nov/Dec 2022 Question Paper- Click Here
  • PH3151 Engineering Physics Nov/Dec 2022 Question Paper- Click Here
  • PH3151 Engineering Physics April/May 2023 Question Paper- Click Here
  • PH3151 Engineering Physics Nov/Dec 2023 Question Paper-  Click Here

Unit-1 (Mechanics)

2 Marks

  1. Define the terms: rotational kinetic energy and moment of inertia?
  2. The classroom door is of width 50cm. If the handle of the door is 20cm from the edge
    and the force of 5N is applied on the handle,computer the torque ?
  3. A clock is mounted on the wall.what is the value of the second hand of the clock?
  4. what are the difference between linear and nonlinear oscillation?
  5. Define center of mass
  6. State law of conservation of angular momentum
  7. State parallel axis theorem
  8. how center of mass is determined for rigid body and regular shape
  9. Mention the characteristic about the energy and momentum of a body at the centre of
    mass
  10. If the force of an oscillation is given by F(x)=-kx-bx²-cx²,what kind of an oscillation is
    this?
  11. Define torque
  12. what is a torsional pendulum?

16 Marks

  1. Explain how the moment of interia of rigid bodies affect their rotational kinetic energy.
  2. Discuss in detail the concept of conservation of angular momentum.
  3. Find the rotational motion equation around a fixed axis. (8mark)
  4. Derive the relation between rotational kinetic energy and moment of interia. (8mark)
  5. Include a description of the gyroscope’s construction, working, and its uses
  6. State and prove parallel and perpendicular acid theorem with a neat sketch
  7. Derive the period of torsional pendulum and arrive at the equation of torsional rigidity
  8. Derive the relation between rotational kinetic energy and moment of inertia and give a
    short note on moment of inertia of a diatomic molecule.
  9. Discuss in detail the rotational energy system of a rigid diatomic molecule
    10.derive the expression for rotational kinetic energy and moment of interia for the rigid
    body in rotation(8mark)
  10. Derive an expression for the moment of interia for a hollow cylinder about its own
    acid and about an axis paint through the centre and perpendicular to its own
    axis.(12mark)
  11. The earth has a mass of 5.9710²⁴kg, and the moon has a mass of 7.3610²²kg. The
    center of the moon is at a distance of 384,000km from the center of earth. Find the centre
    of mass of the earth-moon system from the centre of the earth(4mark)
  12. Discuss in detail the rotational energy states of a diatomic molecule(12mark)
  13. A large disc is spum by applying a torque on the top edge. Assuming a force of 100N
    is exerted through a rotation of 1 rad, find the final angular velocity and rotational kinetic
    energy. Given the radius of the disc is 0.22m and mass is 5kg

Unit-2 (Electromagnetic Waves)

2 Marks 

  1. What is the physical meaning of gauss law of magnetostatics?
  2. A light pulse with a power of 100mW has a duration of 10–⁵s. If it is absorbed
    completely by an object at rest. Find the final momentum of the object.
  3. Write down the properties of Electromagnetic waves
  4. What is polarization?
  5. Define the term radiation pressure. How do Electromagnetic waves have momentum?
  6. Write down the wave equation
  7. Define the term radiation pressure
  8. Write the significance of Maxwell’s equation div. B=0.
  9. Estimate the radiation pressure ‘R’ for a reflected EM wave of the electromagnetic
    wave intensity is’I’
  10. What do polarized sunglasses do to the light entering your eyes?
  11. Write the general electromagnetic wave equation in terms of magnetic field vector in
    free space

16 Marks

  1. Derive the wave equation for plane Electromagnetic waves in vaccum from the
    Maxwell’s equations.
  2. Discuss in detail the production of Electromagnetic waves
  3. Discuss the reflection and transmission of Electromagnetic waves from a non
    conducting medium.
  4. Discuss the source of Electromagnetic waves and also mention the properties of
    Electromagnetic waves.
  5. An electromagnetic wave propagates along the x direction. The magnetic field
    purchipaga at a frequency of 10¹⁰Hz with an amplitude of 10–⁵T in y-direction. Compute
    the wavelength of the wave(4mark)
  6. With suitable sketches discuss the details of polarization of EM waves. (10mark)
  7. Calculate the reflection and transmission coefficient of an EM wave propagating from
    air to glass with refractive index 1.5

Unit-3 ( Oscillations, Optics, and Laser)

2 Marks

  1. What are standing waves?
  2. Why is population inversion necessary for laying action?
  3. Define total internal reflection
  4. Differentiate between last and ordinary light
  5. Define the term simple harmonic waves
  6. What is spontaneous emission and simulated emission?
  7. Distinguish between progressive wave and stationary waves.
  8. Calculate the wavelength of light emission from GaAs whose band gap is 3eV.
  9. How will you differentiate travelling and standing wave with respect to energy?
  10. Identify any two properties of laser useful for communication applications
  11. State doppler effect

16 Marks

  1. Explain the energy transfer of a wave
  2. A vehicle has bad suspension system and undergoes oscillation when crossing over a
    bumb. Calculate the frequency and period of oscillation for the vehicles of its mass is 1
    ton and the force constant of the suspension is 2.69*10⁴N/m
  3. Discuss the construction and the working of a CO2 laser with suitable diagrams.(12
    mark)
  4. A point light source 5m below the surface of a water pull produces a circular pattern of
    light when viewed from above. Taking the refractive index of water to be 1.33, find the
    radius of the circle(4 mark)
  5. Derive Einstein co-efficient for spontaneous and simulated emission
  6. State the student analogies between electrical and mechanical oscillating stem and
    write a brief note on standing and travelling waves
  7. Two skins waves from a point source on the ground travel through the ground to a
    detector. The speed of one wave is 5.0 Kms–¹. The wave arrive at the detector 15s apart.
    What is the distance from the point source to the detector? (4 mark)
  8. Explain the principle, construction and working of a semi conductor dose laser with
    necessary diagrams. Mention it’s characteristics, advantage and applications
  9. Explain simple harmonic motion and discuss its characteristics. Hence derive the
    wave equation for standing waves
  10. Outline the principle construction and working of an Nf-YAG laser. List any three
    characteristic, advantages and applications of Nd-YAG laser.
  11. Explain simple harmonic motion and occurri of resonance (8mark)
  12. What is the analogy between electrical and mechanical oscillator(8mark)
  13. Elaborate various emission processes and tabulate the difference between Nd:YAG
    and CO2 laser. (10 mark)
  14. An air wedge is formed by placing a sheet of foil between the edges of two glass
    plates at 75mm from their point of contact. When the wedge is illuminated with light of
    wavelength 5.8*10–⁷m, the fringes are 1.30mm apart. Calculate the thickness of the
    foil(6mark)
  15. How are standing waves produced? Derive the expression for the wave equation for
    standing waves.
  16. What are the processes that happen when light interacts with matter? Derive the
    Einstein’s relation for a two energy level system
  17. Describe how interference fringes form in an air-wedge shaped film. How does this
    procedure calculate the write thickness?
  18. Describe the CO2 molecule vibrational modes. Describe the CO2 laser design and
    operation with the appropriate diagram

Unit-4 (Basic Quantum Mechanics)

2 Marks

  1. State Compton effect.
  2. What are eigen value and eigen function
  3. An electron tailored in a one dimensional infinite potential will has a ground-state
    energy of 1eV. What is the width of the box?
  4. What are matter waves?
  5. What is the physical significance of a wave function
  6. What is Compton effect? Compton effect is not observable in the visible region of
    Electromagnetic spectrum, justify it
  7. Define Compton shift
  8. State the correspondence principle
  9. What is normalisation of wave function in quantum mechanics?

16 Marks

  1. Explain the de-Broglie wave(matter waves)theory and use it to derive the wavelength
    equation associated with a moving particle(8mark)
  2. Derive Schrodinger’s time dependent wave equation(8mark)
  3. Derive an expression for energy levels of a particle enclosed in the 1D infinite potential
    box of with “a”
  4. Derive Schrodinger’s equation both the independent and dependent equation
  5. Derive the eigen function and its corresponding eigenvalues for a particle in an infinite
    potential 1D box
  6. In a Compton scattering event, the scattered photon has an energy of 120KeV andthe
    recoiling electron has an energy of 40KeV. Estimate the photon scattering angle(8mark)
  7. Give the theory of the Compton effect and explain briefly its experimental
    verification
  8. Discuss the normalisation and probability interpretation of a wave function
  9. What is the physical significance of a wave function(4mark)
  10. What do you understand from the correspondence principle (4mark)

Unit-5 (Applied Quantum Mechanics)

2 Marks

  1. Mention some differences between the classical and quantum harmonic oscillator
  2. State Bloch’s theorem
  3. State the principle of resonant diode
  4. What is the quantum harmonic oscillator
  5. What is quantum tunneling
  6. Give a note on the origin of energy bands
  7. What is finite potential well in quantum mechanics

16 Marks

  1. Describe the construction and working of a scanning tunneling microscope with suitable
    diagrams?
  2. Describe the dynamics of a fundamental particle trapped in a one-dimensional will of
    finite potential
  3. Prove the Bloch theorem for particles in a periodic finite potential well
  4. Explain the concept of barrier penetrations and quantum tunneling in detail with
    necessary sketch
  5. Write a brief note on Bloch’s theorem for particles in a periodic perennial and kronig
    Penney model
  6. Discuss the principle, construction, and working of resonant diode
  7. Derive an expression for the harmonic oscillator energy levels by using the
    Schrodinger’s wave equation
  8. With the appropriate diagram, describe the resonant diode’s construction and
    operation

AU Important Questions for 1st Semester Download PDF

Anna University Regulation 2021 important questions for 1st-semester engineering students in the year 2025. All the best for your first 1st-semester examination at Anna University. Here, we have given all the important question banks for Anna University 2021 regulations. You can download the Anna University (AU) regulation 2021 important questions for 1st semester as a PDF. If you’re a first-year Anna University student, use these important questions for your studies.

  • PH3151 Engineering Physics 2-Marks Important Questions- Click Here
  • PH3151 Engineering Physics 16-Marks Important Questions- Click Here
  • GE3151 Problem Solving Using Python Programming Important Question 2025- Click Here
  • MA3151 Matrices and Calculus Important Question 2025- Click Here

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