PRACTICE TEST-3- PAPER-2

PRACTICE TEST THREE 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 solid spherical planet of mass 2m and radius 'R' has a very small tunnel along its diameter. A small cosmic particle of mass m is at a distance 2R from the centre of the planet as shown. Both are initially at rest, and due to gravitational attraction, both start moving toward each other. After some time, the cosmic particle passes through the centre of the planet. (Assume the planet and the cosmic particle are isolated from other planets) 4R (A) Displacement of the cosmic particle till that instant is 3 (B) Acceleration of the cosmic particle at that instant is zero (C) velocity of the cosmic particle at that instant is (D) Total work done by the gravitational force on both the particle is  2Gm2 R 2. At t = 0 the displacement of the block in a linear oscillator executing SHM along an x-axis as shown is – 0.08m. At the same moment t = 0, its velocity is - 1.6 m/s and acceleration is 32 m/s2. –Xm X=0 +Xm (A) Angular freequency of the motion is 20 rad/s. (B) Amplitude of the motion is 11.3 cm.  (C) Phase constant  of the motion if the equation of motion is expressed as x = A sin(t + ) is 4 5 (D) Phase constant  of the motion if the equation of motion is expressed as x = A sin(t + ) is 4 3. A nonconducting disc having uniform positive charge Q, is rotating about its axis with uniform angular velocity . The magnetic field at the center of the disc is. (A) directed outward (B) having magnitude (C) directed inwards (D) having magnitude 0Q 4 R 0Q 2 R 0Q 4 R 0Q 2 R 4. A source emit sound waves of frequency 1000 Hz. The source moves to the right with a speed of 32 m/s relative to ground. On the right a reflecting surface moves towards left with a speed of 64 m/s relative to ground. The speed of sound in air is 332 m/s : (A) wavelength of sound in ahead of source is 0.3 m (B) number of waves arriving per second which meets the reflected surface is 1320 (C) speed of reflected wave is 268 m/s (D) wavelength of reflected waves is nearly 0.2 m 5. In young’s double slit experiment, slits are arranged in such a way that besides central bright fringe, there is only one bright fringe on either side of it. Slit separation d for the given condition cannot be (if  is wavelength of the light used) : (A)  (B) /2 (C) 2 (D) 3/2 6. Two cavities each of radius R/2 are cut from a uniformly charged solid sphere of radius R and charge density  . The centre ‘O’ of the solid sphere is at (0, 0, 0) and the centres of the two cavities cut are at (R/2, 0, 0) and (– R/2, 0, 0) respectively. Then choose the correct option(s) (A) Electric field at all points inside cavity 1 is uniform and is equal to  OA . 30 (B) Electric field at all points inside cavity 2 is uniform and is equal to  . 30 (C) Electric field at A is equal to (D) Electric field at B is equal to  40  40 OA . OB . 7. A closed vessel contains a mixture of two diatomic gases A and B. Molar mass of A is 16 times that of B and mass of gas A, contained in the vessel is 2 times that of B. : (A) Average kinetic energy per molecule of gas A is equal to that of gas B. (B) Root mean square value of translational speed of gas B is four times that of A. (C) Pressure exerted by gas B is eight times of that exerted by gas A. (D) Number of molecules of gas B in the cylinder is eight times that of gas A. 8. A neutron beam, in which each neutron has same kinetic energy, is passed through a sample of hydrogen like gas (but not hydrogen) in ground state and at rest. Due to collision of neutrons with the ions of the gas, ions are excited and then they emit photons. Six spectral lines are obtained in which one of the lines is of wavelength (6200/51) nm. The mass of neutron and proton can be assumed to be nearly same. Use hc = 12400 eVÅ. (A) The gas is helium (B) This gas is lithium (C) minimum possible value of kinetic energy of the neutrons for this to be possible is 63.75 eV (D) minimum possible value of kinetic energy of the neutrons for this to be possible is 12.75 eV 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 Figure shows an irregular wedge of mass m placed on a smooth horizontal surface. Part BC is rough. 9. What minimum velocity should be imparted to a small block of same mass m so that it may reach point B : (A) 2 (B) (C) 2 (D) 10. If the coefficient of friction between the block and wedge is , and the block comes to rest with respect to wedge at a point E on the rough surface then BE will be H (A)  H  h (B)  h (C)  (D) none of these Paragraph for Question Nos. 11 to 12 A steady current 4 A flows in an inductor coil when connected to a 12 V dc source as shown in figure 1. If the same coil is connected to an ac source of 12 V, 50 rad/s, a current of 2.4 A flows in the circuit 1 as shown in figure 2. Now after these observations, a capacitor of capacitance 50 F is connected in series with the coil and with the same AC source as shown in figure 3 : 11. The inductance of the coil is nearly equal to (A) 0.01 H (B) 0.02 H (C) 0.04 H (D) 0.08 H 12. The average power supplied to the circuit after connecting capacitance in series is approximately equal to: (A) 24 W (B) 72 W (C) 144 W (D) None of these Paragraph for Question Nos. 13 to 14 Two circular wire loops each carrying current 'i' lye in two mutually perpendicular planes as shown. Radius of the loop lying in xz–plane is 2R and that lye in xy–plane in R. Current in bigger loop is in clockwise sense and shorter loop it is in anticlockwise sense. There is negligible gap at the point of touch between the two loops. The loops are so adjusted that point P which is the intersection of their axes situated at distance of 2R 3 from the centre of bigger loop and R from the centre of smaller loop. Now, answer the following questions. 13. Ratio of the magnetic field produced at P due to loop–1 and loop–2 : (A) 1 2 1 (B) 2 (C) 3 (D) 3 14. Net magnetic field at point P is : (A) 0i 5 (B) 0i 5 (C) 0i 5 (D) 0i 5 32R 16R 8R 4R Paragraph for Question Nos. 15 to 16 Gold Nucleus ( Au198) can decay into mercury nucleus ( Hg198) by two decay schemes shown in figure. (i) It can emit a  particle ( ) and come to ground state by either emitting one  ray( ) or emitting two  rays ( 1 1 &  ) (ii) It can emit one  particle ( ) and come to ground state by emitting  ray. Atomic masses : 198Au = 197.9682 amu, 198Hg = 197.9662 amu, 1 amu = 930 MeV/c2. The energy levels of the nucleus are shown in figure. 15. What is the maximum kinetic energy of emitted 2 particles (A) 1.44 MeV (B) 0.59 MeV (C) 1.86 MeV (D) 1.46 MeV 16. What is the maximum kinetic energy of emitted  particle is - (A) 1.28 MeV (B) 0.77 MeV (C) 1.86 MeV (D) 0.86 MeV 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. A white light ray is incident on a glass prism, and it create four refracted rays A, B, C and D. Match the refracted rays which are given in List-I with the colours given in List -II (1 & D are rays due to total internal reflection.): List - I List -II Ray Colour (P) A (1) red (Q) B (2) green (R) C (3) yellow (S) D (4) blue Codes : P Q R S (A) 3 1 4 2 (B) 3 1 2 4 (C) 1 3 2 4 (D) 1 3 4 2 18. Three quantities x,y & z are measured such that % error in x is 1%, y is 2% and z is 3%. In List -1 some physical quantity z varies according to the relation given is written. Match the maximum possible percentage error from List 2 to list - 1. List - I List -II x (P) yz x2y (Q) z (1) 7 (2) 9 (R) xy2z (3) 6 x 2 (S) Codes : y 2 z (4) 8 P Q R S (A) 3 1 4 2 (B) 3 1 2 4 (C) 1 3 2 4 (D) 1 3 4 2 19. A sample of gas goes from state A to state B in four different manners, as shown by the graphs. Let W be the work done by the gas and U be change in internal energy along the path AB. Match List  with List  and select the correct answer using the codes given below the lists : List -I List-II V (P) (1) Both W and U are positive P (Q) (2) Both W and U are negative T T (R) (3) W is positive whereas U is negative V P 2P0 (S) P0 V V0 2V0 (4) W is negative whereas U is positive Codes : P Q R S (A) 3 1 4 2 (B) 3 1 2 4 (C) 3 4 1 2 (D) 2 3 1 4 20. Match List  with List  and select the correct answer using the codes given below the lists : List - I List -II (P)  (1) A x  (Q)  (2) A x  A1 x ...... Z1 A1 x ...... Z (R) proton emission (3) A x (S) neutron emission (4) A x   A Z1  A Z 1 x  ...... x  ...... Codes : P Q R S (A) 4 2 3 1 (B) 4 2 1 3 (C) 2 4 1 3 (D) 2 3 1 4 A nswers 1. (A,B,C) 2. (A,B,D) 3. (A,D) 4. (A,B,D) 5. (B,C) 6. (C,D) 7. (A,B,C,D) 8. (A,C) 9. (A) 10. (B) 11. (D) 12. (A) 13. (B) 14. (A) 15. (D) 16. (D) 17. (C) 18. (A) 19. (A) 20. (B)