PRACTICE TEST-2- PAPER-2

PRACTICE TEST TWO PAPER-2 Duration : 3 Hours Max. Marks : 180 GENERAL INSTRUCTIONS 1. The question paper consists of three parts (Physics, Chemistry and Mathematics). Each part consists of three sections and total number of questions are 60. Marking Scheme 2. For each question in Section 1, you will be awarded 3 marks if you darken all the bubble(s) corresponding to only the correct answer(s) and zero mark if no bubbles are darkened. In all other cases, minus one (-1) mark will be awarded. 3. For each question in Section 2 and 3, you will be awarded 3 marks if you darken the bubble corresponding to only the correct answer and zero mark if no bubbles are darkened. In all other cases, minus one (–1) mark will be awarded. PART-A (PHYSICS) SECTION – 1 : (One or more options correct Type) This section contains 8 multiple coice questions. Each question has four choices (A), (B), (C) and (D) out of which ONE or MORE are correct. 1. A satellite revolves around a planet in circular orbit of radius R (much larger than the radius of the planet) with a time period of revolution T. If the satellite is stopped and then released in its orbit (Assume that the satellite experiences gravitational force due to the planet only). (A) It will fall into the planet (B) The time of fall of the satellite is nearly (C) The time of fall of the satellite into the planet is nearly 2T 8 (D) It cannot fall into the planet so time of fall of the satellite is meaningless 2. A block of mass m is placed on a smooth surface and is connected with a spring as shown. The block is pulled by a distance A = 0.10 m from its natural length and released at t = 0. Angular frequency  = K . m   (A) The maximum speed is after t = 20s. (B) Time taken to cover first 0.10 m, t = 20s.   (C) Time taken to cover first 0.05 m, t = 40 s. (D) Time taken to cover first 0.05 m, t = 30s. 3. A circular conducting loop of radius R and carrying current I0(direction not shown) is bent in two equal halves, one lying in x–y plane and other in x–z plane. Centre is at the origin. Loop is immersed in uniform external → 00 ˆ ˆ magnetic field B  2R ( i  k) . If portion in x–y plane experiences a net force in positive y–direction due to external field then : R2  ˆ ˆ (A) Magnetic dipole moment of the loop is 2 0 (k  j) 002 ˆ (B) Net magnetic force due to external field on the portion lying in x–z plane is   j 002R ˆ ˆ ˆ (C) Net torque experience by the loop is (i  j  k) 4 (D) Net magnetic field at the origin is 00 (ˆj  kˆ) 4R 4. A train is moving with constant speed along a circular track. If length of the train is one fourth of length of circular track then which of the following is/are correct options (Assume that sound source is at engine) : (A) Frequency observed by a passenger who is sitting in the middle of train (equidistant from front and rear end) will continuously increase. (B) Frequency observed by a passenger who is sitting in the middle of train (equidistant from front and rear end) will remain constant but more than actual frequency. (C) Frequency observed by a passenger who is sitting in the middle of train (equidistant from front and rear end) will remains constant and equal to actual frequency. (D) Wavelength observed by the person who is on the rear end of train is more than the actual wavelength of sound wave. 5. A student working with sodium light (590 nm) in YDSE puts a thin transparent sheet ( = 1.5) before one of the slits and it appears to him as if position of fringes were remain unchanged. Possible thickness of the sheet is/ are : (A) 1.18 m (B) 2.36 m (C) 3.54 m (D) 4.72 m 6. Two identical dipoles of dipole moment → P  p0 ˆi (p0 is a positive constant) are placed on x-axis at points A(a, 0, 0) and B(–a, 0, 0) as shown. Then pick up the correct statements : x (A) The electric field at each point on y-z plane (except at infinity) must be perpendicular to y-z plane. (B) If electric field exists at a point on y-z plane, it must be perpendicular to y-z plane. (C) Potential at each point on y-z plane is zero. (D) There is a circle of finite radius on y-z plane with centre at origin such that both electric field and potential are zero at each point on its periphery. 7. A gaseous mixture consists of equal number of moles of two ideal gases having adiabatic exponents 1 and 2 and molar specific heats at constant volume Cv and Cv statements is/are correct ? respectively. Which of the following (A) Adiabatic exponent for gaseous mixture is equal to 1   2 2 Cv  Cv (B) Molar specific heat at constant volume for gaseous mixture is equal to 1 2 2 Cv  Cv  R (C) Molar specific heat at constant pressure for gaseous mixture is equal to 1 2 2 (D) Adiabatic exponent for gaseous mixture is 1 + 2R C  C 1 2 8. The figure above shows an energy level diagram for the hydrogen atom. Several transitions are marked as   , . The diagram is only indicative and not to scale.  4 3 2 1 (A) The transition in which a Balmer series photon absorbed is VI. (B) The wavelength of the radiation involved in transition  is 486 nm. (C) IV transition will occur when a hydrogen atom is irradiated with radiation of wavelength 103nm. (D) IV transition will emit the longest wavelength line in the visible portion of the hydrogen spectrum. SECTION – 2 : (Paragraph Type) This section contains 4 paragraphs each describing theory, experiment, data etc. Eight questions relate to four paragraphs with two questions on each paragraph. Each question of a paragraph has only one correct answer among the four choices (A), (B), (C) and (D). Paragraph for Question Nos. 9 to 10 A small block of mass m is fixed at upper end of a massless vertical spring of spring constant K = 4mg L and natural length '10L'. The lower end of spring is free and is at a height L from fixed horizontal floor as shown. The spring is initially unstressed and the spring-block system is released from rest in the shown position. 9. As the block is coming down, the maximum speed attained by the block is (A) (B) (C) (D) 10. Till the block reaches its lowest position for the first time, the time duration for which the spring remains compressed is (A)  (C)  + 1 sin–1 3  (D) 2 + 1 sin–1 3 Paragraph for Question Nos. 11 to 12 A voltage source V = V0 sin (100 t) is connected to a black box in which there can be either one element out of L, C, R or any two of them connected in series. At steady state the variation of current in the circuit and the source voltage are plotted together with time, using an oscilloscope, as shown c.) 11. The element(s) present in black box is/are : (A) only C (B) L C (C) L and R (D) R and C 12. Values of the parameters of the elements, present in the black box are - (A) R = 50 , C = 200 µF (B) R = 50 , L = 2mH (C) R = 400  , C = 50 µ F (D) None of these Paragraph for Question Nos. 13 to 14 A beam of atomic and subatomic particles is incident normally on a region of thickness d which contain a uniform field B. There is no field outside this region. The beam contain electrons, protons, neutrons and  (alpha) particles. 13. If each particle has same momentum initially and each particle emerges out in region III then the minimum value of this momentum is (e = electronic charge) - (A) eBd (B) eBd (C) 2eBd (D) zero 2 14. If each particle had same momentum initially and all particles except one type of particle return back to region I, then the maximum value of this momentum is - (A) eBd (B) eBd (C) 2eBd (D) zero 2 Paragraph for Question Nos. 15 to 16 The radionuclide 56Mn is being produced in a cyclotron at a constant rate P by bombarding a maganese target with deutrons. 56Mn has a half life of 2.5 hours and the target contains large number of only the stable maganese isotope 55Mn. The reaction that produces 56Mn is : 55Mn + d  56Mn + p After being bombarded for a long time, the activity of 56Mn becomes constant equal to 13.86 × 1010 s– 1 . (Use ln2 = 0.693; Avogadro No = 6 × 1023; atomic weight 56Mn = 56 gm/mole) 15. After the activity of 56Mn becomes constant, number of 56Mn nuclei present in the target, is equal to (A) 5 × 1011 (B) 20 × 1011 (C) 1.2 × 1014 (D) 1.8 × 1015 16. After a long time bombardment, number of 56Mn nuclei present in the target depends upon (a) the number of 56Mn nuclei present at the start of the process. (b) half life of the 56Mn (c) the constant rate of production P. (A) All (a), (b) and (c) are correct (B) only (a) and (b) are correct (C) only (b) and (c) are correct (D) only (a) and (c) are correct SECTION – 3 : (Matching List Type) This section contains 4 multiple choice questions. Each questions has matching lists. The codes for the lists have choices (A), (B), (C) and (D) out of which ONLY ONE is correct. 17. An eagle and fish they are along the same straight line as shown in figure. Eagle is coming down with speed 6cm/s, fish going down with speed 8cm/s and water level is decreasing with rate 2cm/s. Match the value of physical quantity given in list -1 from list-2 and select the correct answer using the codes given below the List. List - 1 List - 2 (P) speed of eagle as seen by fish (1) 2 cm/s (Q) speed of fish an seen by eagle (2) VEF = 2 cm/s 3 (R) magnitude of rate of change in distance b/w eagle (3) VFE and fish = 1 cm/s 2 (S) magnitude of rate of change in distance b/w water (4) 4 cm/s level and eagle . Codes : P Q R S (A) 2 3 4 1 (B) 3 2 4 1 (C) 3 1 4 2 (D) 2 3 1 4 18. A particle is performing rectilinear motion on x axis , such that its x- cordinate varies with time as t3 x = –2t2 +3t +5 (m) where t is in second. In List - 1 time instant is given and List-2 sign of velocity and 3 acceleration is given. Match the proper entry from List-2 to List-1 and select the correct answer using the codes given below the list List - 1 List - 2 2 2 2 Codes : P Q R S (A) 4 3 2 1 (B) 4 3 1 2 (C) 2 3 1 4 (D) 2 3 4 1 19. One mole of an ideal gas undergoes a cyclic process ABCD. T-V curve for the process is shown. Q, W and U are heat supplied to the gas, work done by the gas and change in internal energy of gas . Match the proper entry from List -2 to List-1 and select the correct answer using the codes below. List-1 List- 2 (P) AB (1) Q = 3 RT 2 0 (Q) BC (2) W = –2RT0 ln2 (R) CD (3) Q = RT0 ln2 U = –3 RT 2 0 20. Match the proper entries from List -II to List-I and select the correct answer using the codes below. List-I List-II (P) If photons of ultraviolet light of energy 12 eV (1) 8 are incident on a metal surface of work function of 4 eV, then the stopping potential (in eV) will be (Q) The ratio of wavelengths of K lines of two (2) 3  85 2 elements is  81  Number of elements having   atomic numbers between these elements will be (R) If 20 gm of a radioactive substance due to radioactive (3) 12 decay reduces to 10 gm in 4 minutes, then in what time (in minutes) 160 gm of the same substance will reduce to 20 gm (S) The mass defect for the nucleus of helium is (4) 7 0.0302a.m.u. The binding energy per nucleon for helium in MeV is approximately (1amu = 930 MeV/c2) Codes : P Q R S (A) 1 2 3 4 (B) 1 2 4 3 (C) 2 3 4 1 (D) 2 3 1 4 A nswers 1. (A,C) 2. (A,B,D) 3. ( D ) 4. (C,D) 5. (A,B,C,D) 6. (B,C,D) 7. (B,D) 8. (A,B,D) 9. (C) 10. (B) 11. (D) 12. (A) 13. (C) 14. (B) 15. (D) 16. (C) 17. (D) 18. (A) 19. (A) 20. (A)