PRACTICE TEST-2-Paper - 1

PRACTICE TEST TWO PAPER-1 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 2 marks if you darken the bubble corresponding to the correct answer each zero mark if no bubbles are darkened. No negative marks will be awarded for incorrect answers in this section. 3. For each question in Section 2, you will be awarded 4 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. 4. For each question in Section 3, you will be awarded 4 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-I (PHYSICS) SECTION-1 : (Only One option correct type) This section contains 10 multiple choice qustions. Each question has four choices (A), (B), (C) and (D) out of which ONLY ONE is correct. 1. Block ‘ A ‘ is hanging from a vertical spring and is at rest. Block ‘ B ‘ strikes the block ‘A’ with velocity ‘ v ‘ and sticks to it. Then the value of ‘ v ‘ for which the spring just attains natural length is: (A) (B) (C) (D) none of these 2. Radii of curvature of a concavo-convex lens (refractive index = 1.5) are 40 cm (concave side) and 20 cm (convex side) as shown. The convex side is silvered. The distance x on the principal axis where an object is placed so that its image is created on the object itself, is equal to : R = 40 cm R = 20 cm (A) 12 cm (B) 15 cm (C) 16 cm (D) 24 cm 3. The readings of a constant potential difference is noted four times by a student. The student averages these readings but does not take into account the zero error of the voltmeter. The average measurement of the potential difference is Reading 1 1.176 V Reading 2 1.178 V Reading 3 1.177 V Reading 4 1.176 V (A) precise and accurate (B) precise but not accurate (C) accurate but not precise (D) not accurate and not precise 4. In the figure shown the potential energy U of a particle is plotted against its position ' x ' from origin. Then which of the following statement is correct. A particle at : (A) x1 is in stable equilibrium (B) x2 is in stable equilibrium (C) x3 is in stable equilibrium (D) none of these 5. In the figure (i) an extensible string is fixed at one end and the other end is pulled by a tension T. In figure (ii) another identical string is pulled by tension 'T' at both the ends. The ratio of elongation in equilibrium of string in (i) to the elongation of string in (ii) is (A) 1 : 1 (B) 1 : 2 (C) 2 : 1 (D) 0 6. A linear object AB is placed along the axis of a concave mirror. The object is moving towards the mirror with speed V. The speed of the image of the point A is 4 V and the speed of the image of B is also 4V. If centre of the line AB is at a distance L from the mirror then length of the object AB will be (A) 3L 2 5L (B) 3 4L (C) L (D) 3 7. The wall of a house is made of two different materials of same thickness. The temperature of the outer wall is T2 and that of inner wall is T1 < T2. The temperature variation inside the wall as shown in the figure. Then : (A) thermal conductivity of inner wall is greater than that of outer. (B) thermal conductivity of outer wall is greater than that of inner (C) thermal conductivities of the two are equal (D) no conclusion can be drawn about thermal conductivities 8. In a photoelectric experiment, with light of wavelength , the fastest electron has speed v. If the exciting 3 wavelength is changed to 4 (A) v (C) less than v , the speed of the fastest emitted electron will become (B) v (D) greater than v 9. Two coherent light sources P and Q each of wavelength  are separated by a distance 3  as shown . The maximum number of minima formed on line AB which runs from -  to +  is : (A) 2 (B) 4 (C) 6 (D) 8 10. The average rotational kinetic energy of hydrogen molecule at a temperature T is E. The average transla- tional kinetic energy of helium at same temperature will be : 2E (A) 3 5E (B) 3 (C) E (D) 3E 2 SECTION-2 : (One or more option correct type) This section contains 5 multiple choice qustions. Each question has four choices (A), (B), (C) and (D) out of which ONE or MORE are correct. 11. In front of an earthed conductor a point charge + q is placed as shown in figure : (A) On the surface of conductor the net charge is always negative. (B) On the surface of conductor at some points charges are negative and at some points charges may be positive distributed non uniformly (C) Inside the conductor electric field due to point charge is non zero (D) None of these 12. A wire of density 9  103 kg/m3 is stretched between two clamps 1 m apart and is stretched to an extension of 4.9  10 -4 metre. Young's modulus of material is 9  1010 N/m2. Then (A) The lowest frequency of standing wave is 35 Hz (B) The frequency of 1st overtone is 70 Hz (C) The frequency of 1st overtone is 105 Hz (D) The stress in the wire is 4.41 × 107 N/m2 13. Two capacitor of 2 F and 3 F are charged to 150 volt and 120 volt respectively. The plates of a capacitor are connected as shown in the figure. A discharged capacitor of capacity 1.5 F falls to the free ends of the wire. Then after the system comes in steady state : (A) Charge on the 1.5 F capacitor will become 180 C. (B) Charge on the 2 F capacitor will become 120 C. (C) +ve charge flows through A from left to right. (D) +ve charge flows through A from right to left. → ˆ 14. A charged particle is projected in magnetic field B = 10 k from origin in x-y plane. The particle moves in a circle and just touches a line y = 5 m at x = 5 3 m. Then (mass of particle = 5 × 10–5 kg , charge = 1µc) - (A) The particle is projected at an angle 60° with x-axis (B) The radius of circle is 10 m (C) speed of particle is 2m/s (D) workdone by magnetic force on the particle is zero. 15. In the figure shown cross–section area of holes are same and very small in comparison to area of cross– section of water tank : (tanks are the open from the top) (A) x1 : x2 : x3 = (B) x1 : x2 : x3 = : : 6 : 5 : 3 (C) If A1, A2, A3 are the area of streams when it hits the ground then 12A 2 : 5A 2 : 4A 2 = 3 : 3 : 2 (D) If A1, A2, A3 are the area of streams when it hits the ground then 12A 2 : 5A 2 : 4A 2 = 2 : 2 : 3 SECTION-3 : (Integer value correct Type) This section contains 5 questions. The answer to each question is a single digit integer, ranging from 0 to 9 (both inclusive) 16. In the figure shown a thin light inextensible string is wrapped around a uniform disc. One end of the string is fixed to the ceiling of the lift and the other end is fixed to the circumference of the disc. Acceleration ‘a’ of the a lift in such that the centre of disc does not move with respect to ground. Find the value of g . String does not slip on pulley. a 17. Light of intensity = 3W/m2 is incident on a perfectly absorbing metal surface of area 1 m2 making an angle of 600 with the normal.If the force exerted by the photons on the surface is p x10-9 (in Newton) find the value of p. 18. A steel ball falling vertically strikes a fixed rigid plate A with velocity v0 and rebounds horizontally as shown. Assuming surface to be same and the effect of gravity on motion of ball to be neglected. If the coeficient of 1 the restitution for the ball is ‘e’ then find the value of e . 19. Force acting on a particle is → = (y ˆ + xy ˆj ). Find the work done by this force , when particle is moved F i along the line 2x = 3y from origin to the point (3,2) {take all quantities in SI units and  = 1 ,  = 1} 20. An ionisation counter is used to investigate the disintegration rate of a certain radioactive sample. At the start of the experiment, the counter gives 141 pulses in 20s. After 3 days it gives 100 pulses in 20s. Its half life is (in days). A nswers 1. (B) 2. (C) 3. (B) 4. (B) 5. (A) 6. (C) 7. (B) 8. (D) 9. (C) 10. (D) 11. (A,B,C) 12. (A,B) 13. (A,B,C) 14. (A,B,C,D) 15. (A,D) 16. 2 17. 5 18. 3 19. 7 20. 6