Q. Low energy collision (s-wave scattering) of pion (π+) with deuteron (d) results in the production of two protons (𝜋+ + 𝑑 → 𝑝 + 𝑝). The relative orbital angular momentum (in units of ℏ) of the resulting two-proton system for this reaction is (A) 0(B) 1(C) 2(D) 3 Ans: 1 Sol:

Q. An infinitely long wire parallel to the x-axis is kept at 𝑧 = 𝑑 and carries a current I in the positive x direction above a superconductor filling the region 𝑧 ≤ 0 (see figure). The magnetic  field  𝐵⃗→   inside  the  superconductor  is  zero  so  that  the  field  just  outside  the ...

Q. A ball bouncing off a rigid floor is described by the potential energy function Which of the following schematic diagrams best represents the phase space plot of the ball? Ans: Option B Sol:

Q. For the following circuit, the correct logic values for the entries X2 and Y2 in the truth table are (A) 1 and 0                 (B) 0 and 0                  (C) 0 and 1                  (D) 1 and 1 Ans: 1 and 0 

Q. Consider a potential barrier 𝑉(𝑥) of the form: where 𝑉0 is a constant. For particles of energy 𝐸 < 𝑉0 incident on this barrier from the left, which of the following schematic diagrams best represents the probability density |𝜓 (𝑥)|2 as a function of 𝑥. Ans: Option A

Q. A 3-bit analog-to-digital converter is designed to digitize analog signals ranging from 0 V to 10 V. For this converter, the binary output corresponding to an input of 6 V is (A) 011(B) 101(C) 100(D) 010 Ans: 100 Sol:

Q. Consider the motion of a particle along the x-axis in a potential 𝑉(𝑥) = 𝐹|𝑥|. Its ground state energy 𝐸0 is estimated using the uncertainty principle. Then 𝐸0 is proportional to Ans: Option D Sol:

Q. A solid cylinder of radius 𝑅 has total charge 𝑄 distributed uniformly over its volume. It is rotating about its axis with angular speed 𝜔. The magnitude of the total magnetic moment of the cylinder is Ans: Option (C)

Q. The wave function 𝜓(𝑥) of a particle is as shown below Here 𝐾 is a constant, and 𝑎 > 𝑑. The position uncertainty 〈Δ𝑥〉 of the particle is Ans: Option (B)

Q. The  electric   field  of   an   electromagnetic   wave  is   given   by  𝐸⃗→ = 3 sin(𝑘𝑧 − 𝜔𝑡) 𝑥̂ + 4 cos(𝑘𝑧 − 𝜔𝑡) 𝑦̂. The wave is (C) elliptically polarized in clockwise direction when seen travelling towards the observer (D) elliptically polarized in counter-clockwise direction when ...

Q. A conventional type-I superconductor has a critical temperature of 4.7 K at zero magnetic field and a critical magnetic field of 0.3 Tesla at 0 K. The critical field in Tesla at 2 K (rounded off to three decimal places) is Ans: 0.246 Sol:

Q. At temperature T Kelvin (K), the value of the Fermi function at an energy 0.5 eV above the Fermi energy is 0.01. Then T, to the nearest integer, is___________(𝑘B = 8.62 × 10−5 eV/K) Ans: 1262 Sol: