JEE Advanced Physics Syllabus can be referred by the IIT aspirants to get a detailed list of all topics that are important in cracking the entrance examination. JEE Advanced syllabus for Physics has been designed in such a way that it offers very practical and application-based learning to further make it easier for students to understand every concept or topic by correlating it with day-to-day experiences. In comparison to the other two subjects, the syllabus of JEE Advanced for physics is developed in such a way so as to test the deep understanding and application of concepts.

**Q1. Figure represents some of the lower energy levels of the hydrogen atom in simplified form If the transition of an electron from E**

_{4}to E_{2}were associated with the emission of blue light, which one of the following transitions could be associated with the emission of red light?
Solution

(c)
For emission of a photon with greater wavelength, energy gap should be less
Blue light falls in the Balmer series and it is obtained when the atom makes transition from E

_{4}to E_{3}. Red light also falls in the Balmer series and it has a lower frequency compared to blue light. By quantum theory of radiation, the energy change E is proportional to the frequency of electromagnetic radiation f by E=hf. Thus, red light is associated with a smaller energy change from a lower energy level (compared to E_{4}) to the first excited state E_{2}. Hence, the only possible transition that result in the emission of red light is the E_{3}to E_{2}transition**Q2. Magnetic moment due to the motion of the electron in n^th energy of hydrogen atom is proportional to**

**Q3. Consider a hypothetical annihilation of a stationary electron with a stationary positron. What is the wavelength of the resulting radiation?**

**Q4. A neutron having kinetic energy 5 eV is incident on a hydrogen atom in its ground state. The collision**

Solution

**(a)**(a) For a collision of neutron with hydrogen atom in ground state to be inelastic (partial or complete), the minimum KE of striking neutron must be 20.4 eV. [This condition is derived in theory] As the energy of the given incident neutron is less than 2.4 eV, the collision must be elastic**Q5. When an electron accelerated by potential difference U is bombarded on a specific metal, the emitted X-rays spectrum obtained is shown in figure. If the potential difference is reduced to U/3, the correct spectrum is**

Solution

(b) Î»

(b) Î»

_{m}will increase to 3Î»_m due to decrease in the energy of bombarding electrons. Hence, no characteristic X-rays will be visible, only continuous X-ray will be produced**Q6. The orbital velocity of an electron in the ground state is v. If the electron is excited to energy state -0.54 eV, its orbital velocity will be**

**Q7. If the average life time of an excited state of hydrogen is of the order of 10**

^{(-8)}s, then the number of revolutions an electron will make when it is in n=2 state before coming to ground state will be [Take a_{0}=0.53 â„« and all standard data if required]**Q8. If an electron in n=3 orbit of hydrogen atom jumps down to n=2 orbit, the amount of energy released and the wavelength of radiation emitted are**

**Q9. A proton of mass m moving with a speed v_0 approaches a stationary proton that is free to move. Assume impact parameter to be zero, i.e., head-on collision. How close will the incident proton go to other proton?**

**Q10. In which of the following systems will the radius of the first orbit (n=1) be minimum?**

Solution

(a) Radius of first orbit, r∝1/Z. For doubly ionized lithium, Z will be maximum. Hence, for doubly ionized lithium r will be minimum

(a) Radius of first orbit, r∝1/Z. For doubly ionized lithium, Z will be maximum. Hence, for doubly ionized lithium r will be minimum