Download, print and study this document offline |
Page 1 1 FINAL JEE –MAIN EXAMINATION – JUNE, 2022 (Held On Tuesday 28 th June, 2022) TIME : 3 : 00 PM to 6 : 00 PM PHYSICS TEST PAPER WITH SOLUTION SECTION-A 1. Velocity (v) and acceleration (a) in two systems of units 1 and 2 are related as ? 21 2 n vv m and 1 2 a a mn ? respectively. Here m and n are constants. The relations for distance and time in two systems respectively are: (A) 32 1 2 1 2 3 nn L L and T T mm ?? (B) 42 1 2 1 2 2 nn L L andT T mm ?? (C) 24 1 2 1 2 2 nn L L and T T mm ?? (D) 24 1 2 1 2 2 nn L L and T T mm ?? Official Ans. by NTA (A) Sol. 21 2 21 LL n TT m ? 21 22 21 LL T T mn ? ? 2 22 22 1 1 TT n T m T mn ?? ? 2 2 1 T n mT ? 4 2 2 1 L n1 L mn m ?? 3 2 3 1 L n L m ? 2. A ball is spun with angular acceleration ? ? ? 2 6t 2t where t is in second and ? is in rads –2 . At t = 0, the ball has angular velocity of 10 rads –1 and angular position of 4 rad. The most appropriate expression for the angular position of the ball is: (A) 42 3 t t 10t 2 ?? (B) 43 tt 10t 4 23 ? ? ? (C) 43 2t t 10t 12 36 ? ? ? (D) 3 4 t 2t 5t 4 2 ? ? ? Official Ans. by NTA (B) Sol. 2 dw 6t 2t dt ?? w 32 10 dw 2t t ?? ? 32 w 10 2t t ? ? ? 32 d 10 2t t dt ? ? ? ? 32 4 d 10 2t t ? ? ? ? ? ? ? ? ? ? ? ? 43 4 tt d 10t 23 43 tt 4 10t 23 ? ? ? ? ? Page 2 1 FINAL JEE –MAIN EXAMINATION – JUNE, 2022 (Held On Tuesday 28 th June, 2022) TIME : 3 : 00 PM to 6 : 00 PM PHYSICS TEST PAPER WITH SOLUTION SECTION-A 1. Velocity (v) and acceleration (a) in two systems of units 1 and 2 are related as ? 21 2 n vv m and 1 2 a a mn ? respectively. Here m and n are constants. The relations for distance and time in two systems respectively are: (A) 32 1 2 1 2 3 nn L L and T T mm ?? (B) 42 1 2 1 2 2 nn L L andT T mm ?? (C) 24 1 2 1 2 2 nn L L and T T mm ?? (D) 24 1 2 1 2 2 nn L L and T T mm ?? Official Ans. by NTA (A) Sol. 21 2 21 LL n TT m ? 21 22 21 LL T T mn ? ? 2 22 22 1 1 TT n T m T mn ?? ? 2 2 1 T n mT ? 4 2 2 1 L n1 L mn m ?? 3 2 3 1 L n L m ? 2. A ball is spun with angular acceleration ? ? ? 2 6t 2t where t is in second and ? is in rads –2 . At t = 0, the ball has angular velocity of 10 rads –1 and angular position of 4 rad. The most appropriate expression for the angular position of the ball is: (A) 42 3 t t 10t 2 ?? (B) 43 tt 10t 4 23 ? ? ? (C) 43 2t t 10t 12 36 ? ? ? (D) 3 4 t 2t 5t 4 2 ? ? ? Official Ans. by NTA (B) Sol. 2 dw 6t 2t dt ?? w 32 10 dw 2t t ?? ? 32 w 10 2t t ? ? ? 32 d 10 2t t dt ? ? ? ? 32 4 d 10 2t t ? ? ? ? ? ? ? ? ? ? ? ? 43 4 tt d 10t 23 43 tt 4 10t 23 ? ? ? ? ? 2 3. A block of mass 2 kg moving on a horizontal surface with speed of 4 ms -1 enters a rough surface ranging from x = 0.5 m to x = 1.5 m. The retarding force in this range of rough surface is related to distance by F kx ?? where k = 12 Nm -1 . The speed of the block as it just crosses the rough surface will be: (A) Zero (B) 1.5 ms -1 (C) 2.0 ms -1 (D) 2.5 ms -1 Official Ans. by NTA (C) Sol. kx 12x a 6x 22 ?? ? ? ? ? vdv 6x dx ?? v 3/2 1 4 2 vdv 6xdx ?? ?? 22 22 v 4 6 3 1 2 2 2 2 ?? ? ? ? ? ? ? ? ? ?? ? ? ? ? ? ? ? ? ?? ?? 2 91 v 16 6 44 ?? ? ? ? ? ?? ?? 2 v 16 6 2 4 ? ? ? ? V = 2 m/s 4. A 34 m long ladder weighing 10 kg leans on a frictionless wall. Its feet rest on the floor 3 m away from the wall as shown in the figure. If F f and F w are the reaction forces of the floor and the wall, then ratio of F w /F f will be: (Use g = 10 m/s 2 ) (A) 6 110 (B) 3 113 (C) 3 109 (D) 2 109 Official Ans. by NTA (C) Sol. 34m N 2 S 3m mg N 1 f ? ? 2 fN 1 N mg ? 2 N sin mg cos 2 ? ? ? ? 2 mg N cot 2 ?? ? ? w 2 f 2 mg cot F 2 F mg mg cot 2 ? ? ?? ?? ?? ?? 2 1 4 1 cot ? ? ? 3 109 ? 5. Water fall from a 40 m high dam at the rate of ? 4 9 10 kg per hour. Fifty percentage of gravitational potential energy can be converted into electrical energy. Using this hydroelectric energy number of 100W lamps, that can be lit, is: (Take g = 10 ms -2 ) (A) 25 (B) 50 (C) 100 (D) 18 Official Ans. by NTA (B) Sol. 4 9 10 g 40 0.5 n 100 3600 ? ? ? ? ? ? 4 10 0.5 n 100 ? ? 100 × 0.5 = n n = 50 Page 3 1 FINAL JEE –MAIN EXAMINATION – JUNE, 2022 (Held On Tuesday 28 th June, 2022) TIME : 3 : 00 PM to 6 : 00 PM PHYSICS TEST PAPER WITH SOLUTION SECTION-A 1. Velocity (v) and acceleration (a) in two systems of units 1 and 2 are related as ? 21 2 n vv m and 1 2 a a mn ? respectively. Here m and n are constants. The relations for distance and time in two systems respectively are: (A) 32 1 2 1 2 3 nn L L and T T mm ?? (B) 42 1 2 1 2 2 nn L L andT T mm ?? (C) 24 1 2 1 2 2 nn L L and T T mm ?? (D) 24 1 2 1 2 2 nn L L and T T mm ?? Official Ans. by NTA (A) Sol. 21 2 21 LL n TT m ? 21 22 21 LL T T mn ? ? 2 22 22 1 1 TT n T m T mn ?? ? 2 2 1 T n mT ? 4 2 2 1 L n1 L mn m ?? 3 2 3 1 L n L m ? 2. A ball is spun with angular acceleration ? ? ? 2 6t 2t where t is in second and ? is in rads –2 . At t = 0, the ball has angular velocity of 10 rads –1 and angular position of 4 rad. The most appropriate expression for the angular position of the ball is: (A) 42 3 t t 10t 2 ?? (B) 43 tt 10t 4 23 ? ? ? (C) 43 2t t 10t 12 36 ? ? ? (D) 3 4 t 2t 5t 4 2 ? ? ? Official Ans. by NTA (B) Sol. 2 dw 6t 2t dt ?? w 32 10 dw 2t t ?? ? 32 w 10 2t t ? ? ? 32 d 10 2t t dt ? ? ? ? 32 4 d 10 2t t ? ? ? ? ? ? ? ? ? ? ? ? 43 4 tt d 10t 23 43 tt 4 10t 23 ? ? ? ? ? 2 3. A block of mass 2 kg moving on a horizontal surface with speed of 4 ms -1 enters a rough surface ranging from x = 0.5 m to x = 1.5 m. The retarding force in this range of rough surface is related to distance by F kx ?? where k = 12 Nm -1 . The speed of the block as it just crosses the rough surface will be: (A) Zero (B) 1.5 ms -1 (C) 2.0 ms -1 (D) 2.5 ms -1 Official Ans. by NTA (C) Sol. kx 12x a 6x 22 ?? ? ? ? ? vdv 6x dx ?? v 3/2 1 4 2 vdv 6xdx ?? ?? 22 22 v 4 6 3 1 2 2 2 2 ?? ? ? ? ? ? ? ? ? ?? ? ? ? ? ? ? ? ? ?? ?? 2 91 v 16 6 44 ?? ? ? ? ? ?? ?? 2 v 16 6 2 4 ? ? ? ? V = 2 m/s 4. A 34 m long ladder weighing 10 kg leans on a frictionless wall. Its feet rest on the floor 3 m away from the wall as shown in the figure. If F f and F w are the reaction forces of the floor and the wall, then ratio of F w /F f will be: (Use g = 10 m/s 2 ) (A) 6 110 (B) 3 113 (C) 3 109 (D) 2 109 Official Ans. by NTA (C) Sol. 34m N 2 S 3m mg N 1 f ? ? 2 fN 1 N mg ? 2 N sin mg cos 2 ? ? ? ? 2 mg N cot 2 ?? ? ? w 2 f 2 mg cot F 2 F mg mg cot 2 ? ? ?? ?? ?? ?? 2 1 4 1 cot ? ? ? 3 109 ? 5. Water fall from a 40 m high dam at the rate of ? 4 9 10 kg per hour. Fifty percentage of gravitational potential energy can be converted into electrical energy. Using this hydroelectric energy number of 100W lamps, that can be lit, is: (Take g = 10 ms -2 ) (A) 25 (B) 50 (C) 100 (D) 18 Official Ans. by NTA (B) Sol. 4 9 10 g 40 0.5 n 100 3600 ? ? ? ? ? ? 4 10 0.5 n 100 ? ? 100 × 0.5 = n n = 50 3 6. Two objects of equal masses placed at certain distance from each other attracts each other with a force of F. If one-third mass of one object is transferred to the other object, then the new force will be : (A) 2 F 9 (B) 16 F 9 (C) 8 F 9 (D) F Official Ans. by NTA (C) Sol. 2 2 Gm F r ? 2 4m 2m G 33 F' r ? ? ? ? ? ? ? ? ? ? ? ? ? ? 8 F' F 9 ? 7. A water drop of radius ? 1m falls in a situation where the effect of buoyant force is negligible. Co- efficient of viscosity of air is ?? ? 52 1.8 10 Nsm and its density is negligible as compared to that of water ? 63 10 gm . Terminal velocity of the water drop is: (Take acceleration due to gravity = 10 ms –2 ) (A) ?? ? 61 145.4 10 ms (B) ?? ? 61 118.0 10 ms (C) ?? ? 61 132.6 10 ms (D) ?? ? 61 123.4 10 ms Official Ans. by NTA (D) Sol. F = 6 rv vt ?? 4 mg 3 = ?? rg 3 v t 3 t 4 6 rv r g 3 ? ? ? ? ? 3 t 4 r g v 3 6 r ?? ?? ?? 3 12 3 t –5 4 r g 2 10 10 10 v 3 6 r 9 1.8 10 ? ? ? ? ? ? ? ? ? ?? ?? = 123.4 × 10 –6 m/s 8. A sample of an ideal gas is taken through the cyclic process ABCA as shown in figure. It absorbs, 40 J of heat during the part AB, no heat during BC and rejects 60J of heat during CA. A work 50J is done on the gas during the part BC. The internal energy of the gas at A is 1560J. The work done by the gas during the part CA is: (A) 20 J (B) 30 J (C) –30J (D) –60 J Official Ans. by NTA (B) Sol. cycle Q 40 60 W ? ? ? ? ? BC CA W – 2 0J W W ? ? ? ? ? CA BC W – 2 0 J W ? ? ? = –20 – (–50) = 30 J 9. What will be the effect on the root mean square velocity of oxygen molecules if the temperature is doubled and oxygen molecule dissociates into atomic oxygen? (A) The velocity of atomic oxygen remains same (B) The velocity of atomic oxygen doubles (C) The velocity of atomic oxygen becomes half (D) The velocity of atomic oxygen becomes four times Official Ans. by NTA (B) Page 4 1 FINAL JEE –MAIN EXAMINATION – JUNE, 2022 (Held On Tuesday 28 th June, 2022) TIME : 3 : 00 PM to 6 : 00 PM PHYSICS TEST PAPER WITH SOLUTION SECTION-A 1. Velocity (v) and acceleration (a) in two systems of units 1 and 2 are related as ? 21 2 n vv m and 1 2 a a mn ? respectively. Here m and n are constants. The relations for distance and time in two systems respectively are: (A) 32 1 2 1 2 3 nn L L and T T mm ?? (B) 42 1 2 1 2 2 nn L L andT T mm ?? (C) 24 1 2 1 2 2 nn L L and T T mm ?? (D) 24 1 2 1 2 2 nn L L and T T mm ?? Official Ans. by NTA (A) Sol. 21 2 21 LL n TT m ? 21 22 21 LL T T mn ? ? 2 22 22 1 1 TT n T m T mn ?? ? 2 2 1 T n mT ? 4 2 2 1 L n1 L mn m ?? 3 2 3 1 L n L m ? 2. A ball is spun with angular acceleration ? ? ? 2 6t 2t where t is in second and ? is in rads –2 . At t = 0, the ball has angular velocity of 10 rads –1 and angular position of 4 rad. The most appropriate expression for the angular position of the ball is: (A) 42 3 t t 10t 2 ?? (B) 43 tt 10t 4 23 ? ? ? (C) 43 2t t 10t 12 36 ? ? ? (D) 3 4 t 2t 5t 4 2 ? ? ? Official Ans. by NTA (B) Sol. 2 dw 6t 2t dt ?? w 32 10 dw 2t t ?? ? 32 w 10 2t t ? ? ? 32 d 10 2t t dt ? ? ? ? 32 4 d 10 2t t ? ? ? ? ? ? ? ? ? ? ? ? 43 4 tt d 10t 23 43 tt 4 10t 23 ? ? ? ? ? 2 3. A block of mass 2 kg moving on a horizontal surface with speed of 4 ms -1 enters a rough surface ranging from x = 0.5 m to x = 1.5 m. The retarding force in this range of rough surface is related to distance by F kx ?? where k = 12 Nm -1 . The speed of the block as it just crosses the rough surface will be: (A) Zero (B) 1.5 ms -1 (C) 2.0 ms -1 (D) 2.5 ms -1 Official Ans. by NTA (C) Sol. kx 12x a 6x 22 ?? ? ? ? ? vdv 6x dx ?? v 3/2 1 4 2 vdv 6xdx ?? ?? 22 22 v 4 6 3 1 2 2 2 2 ?? ? ? ? ? ? ? ? ? ?? ? ? ? ? ? ? ? ? ?? ?? 2 91 v 16 6 44 ?? ? ? ? ? ?? ?? 2 v 16 6 2 4 ? ? ? ? V = 2 m/s 4. A 34 m long ladder weighing 10 kg leans on a frictionless wall. Its feet rest on the floor 3 m away from the wall as shown in the figure. If F f and F w are the reaction forces of the floor and the wall, then ratio of F w /F f will be: (Use g = 10 m/s 2 ) (A) 6 110 (B) 3 113 (C) 3 109 (D) 2 109 Official Ans. by NTA (C) Sol. 34m N 2 S 3m mg N 1 f ? ? 2 fN 1 N mg ? 2 N sin mg cos 2 ? ? ? ? 2 mg N cot 2 ?? ? ? w 2 f 2 mg cot F 2 F mg mg cot 2 ? ? ?? ?? ?? ?? 2 1 4 1 cot ? ? ? 3 109 ? 5. Water fall from a 40 m high dam at the rate of ? 4 9 10 kg per hour. Fifty percentage of gravitational potential energy can be converted into electrical energy. Using this hydroelectric energy number of 100W lamps, that can be lit, is: (Take g = 10 ms -2 ) (A) 25 (B) 50 (C) 100 (D) 18 Official Ans. by NTA (B) Sol. 4 9 10 g 40 0.5 n 100 3600 ? ? ? ? ? ? 4 10 0.5 n 100 ? ? 100 × 0.5 = n n = 50 3 6. Two objects of equal masses placed at certain distance from each other attracts each other with a force of F. If one-third mass of one object is transferred to the other object, then the new force will be : (A) 2 F 9 (B) 16 F 9 (C) 8 F 9 (D) F Official Ans. by NTA (C) Sol. 2 2 Gm F r ? 2 4m 2m G 33 F' r ? ? ? ? ? ? ? ? ? ? ? ? ? ? 8 F' F 9 ? 7. A water drop of radius ? 1m falls in a situation where the effect of buoyant force is negligible. Co- efficient of viscosity of air is ?? ? 52 1.8 10 Nsm and its density is negligible as compared to that of water ? 63 10 gm . Terminal velocity of the water drop is: (Take acceleration due to gravity = 10 ms –2 ) (A) ?? ? 61 145.4 10 ms (B) ?? ? 61 118.0 10 ms (C) ?? ? 61 132.6 10 ms (D) ?? ? 61 123.4 10 ms Official Ans. by NTA (D) Sol. F = 6 rv vt ?? 4 mg 3 = ?? rg 3 v t 3 t 4 6 rv r g 3 ? ? ? ? ? 3 t 4 r g v 3 6 r ?? ?? ?? 3 12 3 t –5 4 r g 2 10 10 10 v 3 6 r 9 1.8 10 ? ? ? ? ? ? ? ? ? ?? ?? = 123.4 × 10 –6 m/s 8. A sample of an ideal gas is taken through the cyclic process ABCA as shown in figure. It absorbs, 40 J of heat during the part AB, no heat during BC and rejects 60J of heat during CA. A work 50J is done on the gas during the part BC. The internal energy of the gas at A is 1560J. The work done by the gas during the part CA is: (A) 20 J (B) 30 J (C) –30J (D) –60 J Official Ans. by NTA (B) Sol. cycle Q 40 60 W ? ? ? ? ? BC CA W – 2 0J W W ? ? ? ? ? CA BC W – 2 0 J W ? ? ? = –20 – (–50) = 30 J 9. What will be the effect on the root mean square velocity of oxygen molecules if the temperature is doubled and oxygen molecule dissociates into atomic oxygen? (A) The velocity of atomic oxygen remains same (B) The velocity of atomic oxygen doubles (C) The velocity of atomic oxygen becomes half (D) The velocity of atomic oxygen becomes four times Official Ans. by NTA (B) 4 Sol. rms 3RT V M ? T ? 2T M M 2 ? rms T V M ? ? ? ? ? ? ? rms rms rms atomic molecular molecular 2 V V 2 V 1 / 2 ? ? ? ? 10. Two point charges A and B of magnitude ? ?? 6 8 10 C and ? ?? 6 8 10 C respectively are placed at a distance d apart. The electric field at the middle point O between the charges is ? ? 41 6.4 10 NC . The distance ‘d’ between the point charges A and B is: (A) 2.0 m (B) 3.0 m (C) 1.0 m (D) 4.0 m Official Ans. by NTA (B) Sol. –q +q O E – E + ? ? 0 2 Kq E2 d / 2 ?? 0 2 Kq E8 d ?? 96 2 4 8 9 10 8 10 d 6.4 10 ? ? ? ? ? ?? ? d = 3 m 11. Resistance of the wire is measured as ? 2 and ? 3 at 10°C and 30°C respectively. Temperature co– coefficient of resistance of the material of the wire is : (A) 0.033°C –1 (B) –0.033°C –1 (C) 0.011°C –1 (D) 0.055°C –1 Official Ans. by NTA (A) Sol. ? ? 0 R R 1 T ? ? ? ? ? ? ? ? 0 3 R 1 3 0 – 0 ? ? ? ? ? ? ? 0 2 R 1 1 0 – 0 ? ? ? 3 1 30 2 1 10 ?? ? ?? 1 0.033 30 ? ? ? 12. The space inside a straight current carrying solenoid is filled with a magnetic material having magnetic susceptibility equal to ? ? 5 1.2 10 . What is fractional increase in the magnetic field inside solenoid with respect to air as medium inside the solenoid? (A) ? ? 5 1.2 10 (B) ? ? 3 1.2 10 (C) ? ? 3 1.8 10 (D) ? ? 5 2.4 10 Official Ans. by NTA (A) Sol. 5 1.2 10 ? ? ? ? 5 r 1 1 1.2 10 ? ? ? ? ? ? ? ? Fractional Change ? ? 0 r 0 r 0 ni ni B 1 B ni ? ? ? ? ? ? ? ? ? ? ? = 1.2 × 10 –5 13. Two parallel, long wires are kept 0.20 m apart in vacuum, each carrying current of x A in the same direction. If the force of attraction per meter of each wire is ? ? 6 2 10 N , then the value of x is approximately: (A) 1 (B) 2.4 (C) 1.4 (D) 2 Official Ans. by NTA (C) Page 5 1 FINAL JEE –MAIN EXAMINATION – JUNE, 2022 (Held On Tuesday 28 th June, 2022) TIME : 3 : 00 PM to 6 : 00 PM PHYSICS TEST PAPER WITH SOLUTION SECTION-A 1. Velocity (v) and acceleration (a) in two systems of units 1 and 2 are related as ? 21 2 n vv m and 1 2 a a mn ? respectively. Here m and n are constants. The relations for distance and time in two systems respectively are: (A) 32 1 2 1 2 3 nn L L and T T mm ?? (B) 42 1 2 1 2 2 nn L L andT T mm ?? (C) 24 1 2 1 2 2 nn L L and T T mm ?? (D) 24 1 2 1 2 2 nn L L and T T mm ?? Official Ans. by NTA (A) Sol. 21 2 21 LL n TT m ? 21 22 21 LL T T mn ? ? 2 22 22 1 1 TT n T m T mn ?? ? 2 2 1 T n mT ? 4 2 2 1 L n1 L mn m ?? 3 2 3 1 L n L m ? 2. A ball is spun with angular acceleration ? ? ? 2 6t 2t where t is in second and ? is in rads –2 . At t = 0, the ball has angular velocity of 10 rads –1 and angular position of 4 rad. The most appropriate expression for the angular position of the ball is: (A) 42 3 t t 10t 2 ?? (B) 43 tt 10t 4 23 ? ? ? (C) 43 2t t 10t 12 36 ? ? ? (D) 3 4 t 2t 5t 4 2 ? ? ? Official Ans. by NTA (B) Sol. 2 dw 6t 2t dt ?? w 32 10 dw 2t t ?? ? 32 w 10 2t t ? ? ? 32 d 10 2t t dt ? ? ? ? 32 4 d 10 2t t ? ? ? ? ? ? ? ? ? ? ? ? 43 4 tt d 10t 23 43 tt 4 10t 23 ? ? ? ? ? 2 3. A block of mass 2 kg moving on a horizontal surface with speed of 4 ms -1 enters a rough surface ranging from x = 0.5 m to x = 1.5 m. The retarding force in this range of rough surface is related to distance by F kx ?? where k = 12 Nm -1 . The speed of the block as it just crosses the rough surface will be: (A) Zero (B) 1.5 ms -1 (C) 2.0 ms -1 (D) 2.5 ms -1 Official Ans. by NTA (C) Sol. kx 12x a 6x 22 ?? ? ? ? ? vdv 6x dx ?? v 3/2 1 4 2 vdv 6xdx ?? ?? 22 22 v 4 6 3 1 2 2 2 2 ?? ? ? ? ? ? ? ? ? ?? ? ? ? ? ? ? ? ? ?? ?? 2 91 v 16 6 44 ?? ? ? ? ? ?? ?? 2 v 16 6 2 4 ? ? ? ? V = 2 m/s 4. A 34 m long ladder weighing 10 kg leans on a frictionless wall. Its feet rest on the floor 3 m away from the wall as shown in the figure. If F f and F w are the reaction forces of the floor and the wall, then ratio of F w /F f will be: (Use g = 10 m/s 2 ) (A) 6 110 (B) 3 113 (C) 3 109 (D) 2 109 Official Ans. by NTA (C) Sol. 34m N 2 S 3m mg N 1 f ? ? 2 fN 1 N mg ? 2 N sin mg cos 2 ? ? ? ? 2 mg N cot 2 ?? ? ? w 2 f 2 mg cot F 2 F mg mg cot 2 ? ? ?? ?? ?? ?? 2 1 4 1 cot ? ? ? 3 109 ? 5. Water fall from a 40 m high dam at the rate of ? 4 9 10 kg per hour. Fifty percentage of gravitational potential energy can be converted into electrical energy. Using this hydroelectric energy number of 100W lamps, that can be lit, is: (Take g = 10 ms -2 ) (A) 25 (B) 50 (C) 100 (D) 18 Official Ans. by NTA (B) Sol. 4 9 10 g 40 0.5 n 100 3600 ? ? ? ? ? ? 4 10 0.5 n 100 ? ? 100 × 0.5 = n n = 50 3 6. Two objects of equal masses placed at certain distance from each other attracts each other with a force of F. If one-third mass of one object is transferred to the other object, then the new force will be : (A) 2 F 9 (B) 16 F 9 (C) 8 F 9 (D) F Official Ans. by NTA (C) Sol. 2 2 Gm F r ? 2 4m 2m G 33 F' r ? ? ? ? ? ? ? ? ? ? ? ? ? ? 8 F' F 9 ? 7. A water drop of radius ? 1m falls in a situation where the effect of buoyant force is negligible. Co- efficient of viscosity of air is ?? ? 52 1.8 10 Nsm and its density is negligible as compared to that of water ? 63 10 gm . Terminal velocity of the water drop is: (Take acceleration due to gravity = 10 ms –2 ) (A) ?? ? 61 145.4 10 ms (B) ?? ? 61 118.0 10 ms (C) ?? ? 61 132.6 10 ms (D) ?? ? 61 123.4 10 ms Official Ans. by NTA (D) Sol. F = 6 rv vt ?? 4 mg 3 = ?? rg 3 v t 3 t 4 6 rv r g 3 ? ? ? ? ? 3 t 4 r g v 3 6 r ?? ?? ?? 3 12 3 t –5 4 r g 2 10 10 10 v 3 6 r 9 1.8 10 ? ? ? ? ? ? ? ? ? ?? ?? = 123.4 × 10 –6 m/s 8. A sample of an ideal gas is taken through the cyclic process ABCA as shown in figure. It absorbs, 40 J of heat during the part AB, no heat during BC and rejects 60J of heat during CA. A work 50J is done on the gas during the part BC. The internal energy of the gas at A is 1560J. The work done by the gas during the part CA is: (A) 20 J (B) 30 J (C) –30J (D) –60 J Official Ans. by NTA (B) Sol. cycle Q 40 60 W ? ? ? ? ? BC CA W – 2 0J W W ? ? ? ? ? CA BC W – 2 0 J W ? ? ? = –20 – (–50) = 30 J 9. What will be the effect on the root mean square velocity of oxygen molecules if the temperature is doubled and oxygen molecule dissociates into atomic oxygen? (A) The velocity of atomic oxygen remains same (B) The velocity of atomic oxygen doubles (C) The velocity of atomic oxygen becomes half (D) The velocity of atomic oxygen becomes four times Official Ans. by NTA (B) 4 Sol. rms 3RT V M ? T ? 2T M M 2 ? rms T V M ? ? ? ? ? ? ? rms rms rms atomic molecular molecular 2 V V 2 V 1 / 2 ? ? ? ? 10. Two point charges A and B of magnitude ? ?? 6 8 10 C and ? ?? 6 8 10 C respectively are placed at a distance d apart. The electric field at the middle point O between the charges is ? ? 41 6.4 10 NC . The distance ‘d’ between the point charges A and B is: (A) 2.0 m (B) 3.0 m (C) 1.0 m (D) 4.0 m Official Ans. by NTA (B) Sol. –q +q O E – E + ? ? 0 2 Kq E2 d / 2 ?? 0 2 Kq E8 d ?? 96 2 4 8 9 10 8 10 d 6.4 10 ? ? ? ? ? ?? ? d = 3 m 11. Resistance of the wire is measured as ? 2 and ? 3 at 10°C and 30°C respectively. Temperature co– coefficient of resistance of the material of the wire is : (A) 0.033°C –1 (B) –0.033°C –1 (C) 0.011°C –1 (D) 0.055°C –1 Official Ans. by NTA (A) Sol. ? ? 0 R R 1 T ? ? ? ? ? ? ? ? 0 3 R 1 3 0 – 0 ? ? ? ? ? ? ? 0 2 R 1 1 0 – 0 ? ? ? 3 1 30 2 1 10 ?? ? ?? 1 0.033 30 ? ? ? 12. The space inside a straight current carrying solenoid is filled with a magnetic material having magnetic susceptibility equal to ? ? 5 1.2 10 . What is fractional increase in the magnetic field inside solenoid with respect to air as medium inside the solenoid? (A) ? ? 5 1.2 10 (B) ? ? 3 1.2 10 (C) ? ? 3 1.8 10 (D) ? ? 5 2.4 10 Official Ans. by NTA (A) Sol. 5 1.2 10 ? ? ? ? 5 r 1 1 1.2 10 ? ? ? ? ? ? ? ? Fractional Change ? ? 0 r 0 r 0 ni ni B 1 B ni ? ? ? ? ? ? ? ? ? ? ? = 1.2 × 10 –5 13. Two parallel, long wires are kept 0.20 m apart in vacuum, each carrying current of x A in the same direction. If the force of attraction per meter of each wire is ? ? 6 2 10 N , then the value of x is approximately: (A) 1 (B) 2.4 (C) 1.4 (D) 2 Official Ans. by NTA (C) 5 Sol. Force per unit length = ? ? 0 1 2 ii 2d ?? ? ?? 2 0 x 2 0.2 F = 2 × 10 –6 = ? ? ? ? ?? 72 4 10 x 2 0.2 ?? ?? 2 67 x 10 10 0.2 ? ? ? 2 x 10 0.2 = 2 ? ? ? x 2 1.4 Amp. 14. A coil is placed in a time varying magnetic field. If the number of turns in the coil were to be halved and the radius of wire doubled, the electrical power dissipated due to the current induced in the coil would be: (Assume the coil to be short circuited.) (A) Halved (B) Quadrupled (C) The same (D) Doubled Official Ans. by NTA (D) Sol. P = 2 R ? = 2 C dB NA A dt ?? ? ?? ?? ? P' = 2 C NA dB 4A 2 dt /2 ?? ? ?? ?? ? ? P' = 2P 15. An EM wave propagating in x-direction has a wavelength of 8 mm. The electric field vibrating y- direction has maximum magnitude of 60 Vm –1 . Choose the correct equations for electric and magnetic fields if the EM wave is propagating in vacuum : (A) ? ? ? ??? ? ? ? ? ?? ?? 3 8 1 y ˆ E 60sin 10 x 3 10 t jVm 4 ? ? ??? ? ? ? ? ?? ?? 38 z ˆ B 2sin 10 x 3 10 t kT 4 (B) ? ? ? ??? ? ? ? ? ?? ?? 3 8 1 y ˆ E 60sin 10 x 3 10 t jVm 4 ? ? ? ??? ? ? ? ? ? ?? ?? 7 3 8 z ˆ B 2 10 sin 10 x 3 10 t kT 4 (C) ? ? ?? ??? ? ? ? ? ? ?? ?? 7 3 8 1 y ˆ E 2 10 sin 10 x 3 10 t jVm 4 ? ? ??? ? ? ? ? ?? ?? 38 z ˆ B 60sin 10 x 3 10 t kT 4 (D) ? ? ?? ??? ? ? ? ? ? ?? ?? 7 4 8 1 y ˆ E 2 10 sin 10 x 4 10 t jVm 4 ? ? ??? ? ? ? ? ?? ?? 48 z ˆ B 60sin 10 x 4 10 t kT 4 Official Ans. by NTA (B) Sol. ? ? ? ? ? ? 7 0 0 8 E 60 B 2 10 T c 3 10 ? EB must be direction of propagation. So, ? B z-axis ? ?? ? ? ? ? 31 2 k 10 m 4 ? ??? ? ? ? ? ?? ?? 3 8 1 y E 60sin 10 (x 3 10 t) j Vm 4 ? ??? ? ? ? ? ? ?? ?? 7 3 8 z B 2 10 sin 10 (x 3 10 t) k T 4Read More
254 docs|1 tests
|
1. What is the exam date for JEE Main 2022? |
2. How many shifts were there for the JEE Main 2022 exam on 28 June? |
3. Can I access the JEE Main 2022 Question Paper for 28 June Shift 2 online? |
4. Is it important to solve previous years' JEE Main question papers for better preparation? |
5. How can I utilize the JEE Main 2022 Question Paper for 28 June Shift 2 effectively in my preparation? |
|
Explore Courses for JEE exam
|