Title NT 20 PAPER.pdf ✅

TEACH HIRE CONTENT DEVELOPMENT, PLACEMENTS, TECH SUPPORT JOIN WITH US WANTS TO CHAT?
PHYSICS (Section A) 1. The physical quantity that has unit volt- second is (A) energy (B) electric flux (C) magnetic flux (D) inductance 2. If a projectile is thrown such that range [R] is four times than the height [h] attained then angle of projection is- (A) 30° (B) 45° (C) 60° (D) 90° 3. A river is flowing from west to east at a speed of 5 m./min. A man on the south bank of the river, capable of swimming at 10 m./min. in still water, wants to swim across the river in shortest time. He should swim in a direction- (A) Due north (B) 30° east of north (C) 30° west of north (D) 60° east of north 4. Three block are connected as shown in fig., on a horizontal frictionless table and pulled to the right with a force T3 = 60 N. If m 1 = 10 kg. m2 = 20 kg. and m3 = 30 kg. the tension T2 is- (A) 10 N (B) 20 N (C) 30 N (D) 60 N 5. In which of the following cases forces must not be required to keep the- (A) Particle going in a circle (B) Particle going along a straight line (C) The momentum of the particle constant (D) Acceleration of the particle constant 6. A stone of mass of 16 kg is attached to a string 144 m long and is whirled in a horizontal smooth surface. The maximum tension the string can withstand is 16 newton. The maximum speed of revolution of the stone without breaking it, will be : (A) 20 ms–1 (B) 16 ms–1 (C) 14 ms–1 (D) 12 ms–1 7. A body of mass m starting from rest from origin moves along x-axis with constant power (P). Calculate relation between velocity–distance. (A) 1/2 x v  (B) 2 x v  (C) x v  (D) 3 x v  8. When a body rotates about an axis the quantity which remains same for all its particles, is (A) Liner velocity (B) Angular velocity (C) Linear acceleration (D) Angular momentum 9. The law of conservation of momentum for a system is based on Newton's :- (A) First law of motion (B) Second law of motion (C) Third law of motion (D) Law of gravitation 10. A body of mass m slides down an incline and reaches the bottom with a velocity v. If the same mass were in the form of a ring which rolls down this incline, the velocity of the ring at the bottom would have been : (A) v (B) v 2 (C) v 2 (D) 2 v 5         11. A square brass plate of side 1.0 m and thickness 0.005 m is subjected to a force F on its smaller opposite edges, causing a displacement of 0.02 cm. If the shear modulus of brass is 0.4 × 1011 N/m2 , the value of the force F is (A) 4 × 103 N (B) 400 N (C) 4 × 104 N (D) 1000 N m1 m2 m3 T1 T2 T3 PW – AITS_NT-20
12. Two drops of equal radius are falling through air with a steady velocity of 5cm/sec. If the two drops coalesce, then its terminal velocity will be :– (A) 1 3 4 ×5 cm / s (B) 4 1/3 cm/s (C) 1 3 5 × 4 cm / s (D) 2 3 4 ×5 cm / s 13. When a capillary is dipped in water, water rises 0.015m in it. If the surface tension of water is 75 × 10–3 N/m, the radius of capillary is- (A) 0.1 mm (B) 0.5 mm (C) 1 mm (D) 2 mm 14. An aluminium measuring rod, which is correct at 5°C measures the length of a line as 80 cm at 45°C. If thermal coefficient of linear expansion of aluminium is 2.50 × 10–5 /°C, the correct length of the line is : (A) 80.08 cm (B) 79.92 cm (C) 81.12 cm (D) 79.62 cm 15. A liquid of mass m and specific heat c is heated to a temperature 2T. Another liquid of mass m/2 and specific heat 2c is heated to a temperature T. If these two liquids are mixed, the resulting temperature of the mixture is- (A) (2/3)T (B) (8/5)T (C) (3/5)T (D) (3/2)T 16. A Carnot engine, whose sink is at 300 K, has an efficiency of 40%. By how much the source temperature should be changed so as to increase the efficiency to 60% ? (A) 250K increase (B) 250 K decrease (C) 325K increase (D) 325 K decrease 17. The acceleration due to gravity at height R above the surface of the earth is g/4. The periodic time of a simple pendulum in an artificial satellite at this height will be: (A) T = 2 2 / g  (B) T = 2 / 2g  (C) Zero (D) Infinity 18. Two waves traveling in a medium in the x–direction are represented by y1 = A sin (t – x) and          2 y = Acos x + t – 4 , where y1 and y2 are the displacements of the particles of the medium, t is time, and  and  are constants. The two waves have different:– (A) speeds (B) directions of propagation (C) wavelengths (D) frequencies 19. Potential difference between centre and the surface of sphere of radius R and having uniform volume charge density  within it will be : (A) 2 0 R 6   (B) 2 0 R 4   (C) 0 (D) 2 0 R 2   20. A parallel plate condenser is connected to a battery of e.m.f. 4 volt. If a plate of dielectric constant 8 is inserted into it, then the potential difference on the condenser will be- (A) 1/2 V (B) 2V (C) 4V (D) 32V 21. An infinite ladder network of resistance is constructed with 1 and 2 resistance, as shown in figure. What will be the effective resistance between A and B. (A) 1 (B) 2 (C) 3 (D) 4 22. A wire loop PQRSP is constructed by joining two semi circular coils of radii r1 and r2 respectively as shown in the fig. Current i is flowing in the loop. The magnetic induction at point O will be –
(A) 0 1 2 i 1 1 4 r r      −   (B) 0 1 2 i 1 1 4 r r      +   (C) 0 1 2 i 1 1 2 r r      −   (D) 0 1 2 i 1 1 2 r r      +   23. Which of the following relations is not correct ? (A) B = 0 (H + ) (B) B = 0H ( 1 + m ) (C) 0 =  (1 + m ) (D) r = 1 + m 24. The self-inductances of two identical coils are 0.1 H. They are wound over each other. Mutual inductance will be - (A) 0.1 H (B) 0.2 H (C) 0.01 H (D) 0.05 H 25. A 0.21-H inductor and a 88- resistor are connected in series to a 220-V, 50-Hz AC source. The current in the circuit and the phase angle between the current and the source voltage are respectively. Use  = 22/7. (A) 2 A, tan–1 3/4 (B) 14.4 A, tan–1 7/8 (C) 14.4 A, tan–1 8/7 (D) 3.28 A, tan–1 2/11 26. A series LCR circuit containing a resistance of 120 ohm has angular resonance frequency 4 × 103 rad s–1 . At resonance, the voltage across resistance and inductance are 60V and 40 V respectively. The values of L and C are respectively : (A) 20 mH, 25/8 F (B) 2mH, 1/35 F (C) 20 mH, 1/40 F (D) 2mH, 25/8 nF 27. There is a small black dot at the centre C of a solid glass sphere of refractive index . When seen from outside, the dot will appear to be located: (A) away from C for all values of  (B) at C for all values of  (C) at C for  = 1.5, but away from C for   1.5 (D) at C only for 2    1.5. . A person can see clearly only upto a distance of 25cm. He wants to read a book placed at a distance of 50cm. What kind of lens does he required for his spectacles and what must be its power ? (A) concave, – 1.0 D (B) Convex, + 1. 5 D (C) Concave, – 2.0 D (D) Convex, + 2.0 D 29. In a Young’s double slit experiment the intensity at a point  where the corresponding path difference is one sixth of the wavelength of light used. If 0 denotes the maximum intensity, the ratio 0   is equal to (A) 1 4 (B) 1 2 (C) 3 2 (D) 3 4 30. The stopping potential as a function of frequency of incident radiation is plotted for two different photo electric surfaces A and B. The graphs show the work function of A is (A) Greater than that of B (B) Smaller than that of B (C) Same as that of B (D) No comparison can be done from given graphs 31. The ionization energy of helium atom is 54.4 eV. Helium atoms in the ground state are excited by electromagnetic radiation of energy 51 eV. How many spectral lines will be emitted by the Helium atoms? O r 2 i i S R Q P r1  Vs A B