Tiêu đề Physical Science_2023.pdf ✅

1. At a surface current, which one of the magnetostatic boundary condition is NOT CORRECT? (i) Normal component of the magnetic field is not continuous. (ii) Normal component of the magnetic vector potential is continuous. (iii) Tangential component of the magnetic vector potential is continuous. (iv) Tangential component of the magnetic vector potential is not continuous. Choose the correct answer from the code given below : (A) (i), (iii) (B) (ii), (iv) (C) (iii), (iv) (D) (i), (iv) 2. The product PQ of any two real, symmetric matrices P and Q is : (A) Hermitian for all P and Q (B) Never Symmetric or Hermitian (C) Symmetric, if PQ = QP (D) Anti-Symmetric for all P and Q 3. Given below are two statements, one labelled as Assertion (a) and the other labelled as Reason (r). Read the statements and choose the correct answer from the code given below: Assertion (a): The velocity of all electromagnetic waves in vacuum is different. Reason (r): Because all waves are of different frequency. (A) Both (a) and (r) are true and (r) is correct explanation of (a). (B) Both (a) and (r) are true but (r) is not correct explanation of (a). (C) (a) is true, but (a) is false. (D) (a) is false, but (r) is true. 4. Match List-I and List-II and select the correct answer from the codes given below: List-I P. Phonons Q. Plasmon R. Polarons S. Polariton List-II 1. Quasi particle result from the strong coupling of EM wave 2. Elastic arrangement of atoms and molecules 3. Quasi particle used to understand the interaction between electron and atoms in solid material 4. Quantum of Plasma excitation which means collective electron oscillation Code: (A) P-2 Q-4 R-3 S-1 (B) P -2 Q-3 R-1 S-4 (C) P -3 Q-2 R-1 S-4 (D) P -2 Q-3 R-4 S-1 Total Number of Pages : 32 Paper-II 05-A 3
Total Number of Pages : 32 Paper-II 05-A 4 5. Given below are two statements: Statement I: E : T4 = Constant Statement II: E : T = Constant In light of the above statements, choose the most appropriate answer from the codes given below: (A) Both Statement I and Statement II are correct. (B) Both Statement I and Statement II are incorrect. (C) Statement I is correct but Statement II is incorrect. (D) Statement I is incorrect but Statement II is correct. 6. A rain drop falling vertically under gravity gathers moisture from the atmosphere at a rate given by dm/dt = kt2 , where m is the instantaneous mass, t is time and k is a constant. The equation of motion of the rain drop is mdv/dt +vdm/dt = mg If the drop starts falling at t = 0, with zero initial velocity and initial mass m0 (m0=2gm, k= 12gm/s3 and g=1000 cm/s2 ), the velocity v of the drop after one second is : (A) 250 cm/s (B) 500 cm/s (C) 750 cm/s (D) 1000 cm/s 7. Given below are two statements: Statement I: Newton’s laws of motion and Maxwell’s equations are both invariant under Galilean transformations. Statement II: Newton’s laws of motion are invariant under Galilean transformations and Maxwell’s equations are invariant under Lorentz transformations. In light of the above statements, choose the most appropriate answer from the codes given below: (A) Both Statement I and Statement II are correct. (B) Both Statement I and Statement II are incorrect. (C) Statement I is correct but Statement II is incorrect. (D) Statement I is incorrect but Statement II is correct.