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Through this website, an attempt is being made to provide all the previous year question papers on-line.
Currently work is underway only for the B.Tech. Stream question papers.

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(Please write your Roll No. immediately)

Roll No. ..................................

II Semester Examination

Second Semester [B.Tech]

Paper Code : ETPH – 104 Subject : Applied Physics-II

Time : 1:30 Hours

Maximum Marks : 30

Note : Attempt 3 questions in all. Question 1 is compulsory.

Q.1 Attempt any five parts

  1. An electron and a proton with the same energy E, approach a potential barrier whose height U is greater than E. Do they have the same probability of getting through? Explain your answer with a suitable reason.

  2. Illustruate why an electron cannot exist inside a nucleus.

  3. Find the probability of finding an electron in a sphere of radius r=ao, where the normalised wave function for the electron is Ψ1s=(1/(ao3) exp(-r/ao).

  4. Find the lowest energy of an electron confined in a box of each side 0.2 nm.

  5. Why is the energy of a particle trapped in a box is quantised? Give reasons.

  6. What were the observations of Stern and Gerlach experiment? What phenomenon was explicitly demonstrated by their findings?

  7. A uniformly heated black body enclosure is mantained at 1000o C and radiates energy through an opening 0.3 cm wide. Calculate the energy in calories radiated by the body in one minute.


  1. Derive Planck`s Law of radiation to explain black body spectral line and deduce Rayleigh Jeans Law from Planck's Law.

  2. The resistance of Platinum wire at ice point is 4Ω and at steam point is 6.5Ω. The resistance of the wire is found to be 12Ω when brought in contact with a hot body. Calculate the temperature of the body.

  3. Explain any two of the following:

    1. Thermistor as a temperature control device.

    2. Piezoelectric method for production of ultrasonic waves.

    3. Labelled diagram and working of Platinum resistance thermometer


  1. State and explain Uncertainity Principle.

  2. Find the probability of transmission (tunneling effect) for a particle with energy E, through a 1-dimensional rectangular barrier of height Vo and width a (when E<Vo).

  3. Electrons with energies 2.0 eV are incident on a barrier 10.0 eV high and 0.50 nm wide. Find their approximate transmission probabilities. How are the electrons affected if the barrier is doubled in width?


  1. What is Zeeman effect? Give the Quantum explaination of normal and anomalous Zeeman effect.

  2. Explain any two of the following:

    1. Russel Saunders Coupling scheme

    2. Space Quantisation

    3. Ultrasonography in medicine.

Mass of the electron = 9.1 x 10-31 Kg

Planck's constant = 6.63 x 10-34 J sec

Radius of nucleus = 10-14 m

Stefan's constant = 5.735 x 10-8 J m-2 sec-1 deg-4.