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Page 1 1 FINAL JEE –MAIN EXAMINATION – JUNE, 2022 (Held On Friday 24 th June, 2022) TIME : 9 : 00 AM to 12 : 00 PM PHYSICS TEST PAPER WITH SOLUTION SECTION-A 1. The bulk modulus of a liquid is 3 × 10 10 Nm -2 . The pressure required to reduce the volume of liquid by 2% is : (A) 3 × 10 8 Nm -2 (B) 9 × 10 8 Nm -2 (C) 6 × 10 8 Nm -2 (D) 12 × 10 8 Nm -2 Official Ans. by NTA (C) Sol. B = 3 × 10 10 V 0.02 V ? ?? ?? ?? ? ? ? ? ? ?? ? ?? ? PV B P B V V v 10 (3 10 )(0.02) ?? 82 6 10 N / m ?? 2. Given below are two statements : One is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A) : In an uniform magnetic field, speed and energy remains the same for a moving charged particle. Reason (R) : Moving charged particle experiences magnetic force perpendicular to its direction of motion. (A) Both (A) and (R) are true and (R) is the correct explanation of (A) (B) Both (A) and (R) are true but (R) is NOT the correct explanation of (A) (C) (A) is true but (R) is false (D) (A) is false but (R) is true. Official Ans. by NTA (A) Sol. F q(v B) ?? Fv ? Work done ?? FS Work done = 0 3. Two identical cells each of emf 1.5 V are connected in parallel across a parallel combination of two resistors each of resistance 20?. A voltmeter connected in the circuit measures 1.2 V. The internal resistance of each cell is (A) 2.5 ? (B) 4 ? (C) 5? (D) 10 ? Official Ans. by NTA (C) Sol. 1.5V 1.5V r/2 1.5V r 10 ? 20 ? 20 ? r V = E – ir/2 1.2 = 1.5 – i r 2 ?? ?? ?? r i 0.3 2 ? 1.5 ir i 10i 1.5 r 2 10 2 ? ? ? ? ? 10i = 1.5 – 0.3 i = 0.12 A 0.6 r5 0.12 ? ? ? ? Page 2 1 FINAL JEE –MAIN EXAMINATION – JUNE, 2022 (Held On Friday 24 th June, 2022) TIME : 9 : 00 AM to 12 : 00 PM PHYSICS TEST PAPER WITH SOLUTION SECTION-A 1. The bulk modulus of a liquid is 3 × 10 10 Nm -2 . The pressure required to reduce the volume of liquid by 2% is : (A) 3 × 10 8 Nm -2 (B) 9 × 10 8 Nm -2 (C) 6 × 10 8 Nm -2 (D) 12 × 10 8 Nm -2 Official Ans. by NTA (C) Sol. B = 3 × 10 10 V 0.02 V ? ?? ?? ?? ? ? ? ? ? ?? ? ?? ? PV B P B V V v 10 (3 10 )(0.02) ?? 82 6 10 N / m ?? 2. Given below are two statements : One is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A) : In an uniform magnetic field, speed and energy remains the same for a moving charged particle. Reason (R) : Moving charged particle experiences magnetic force perpendicular to its direction of motion. (A) Both (A) and (R) are true and (R) is the correct explanation of (A) (B) Both (A) and (R) are true but (R) is NOT the correct explanation of (A) (C) (A) is true but (R) is false (D) (A) is false but (R) is true. Official Ans. by NTA (A) Sol. F q(v B) ?? Fv ? Work done ?? FS Work done = 0 3. Two identical cells each of emf 1.5 V are connected in parallel across a parallel combination of two resistors each of resistance 20?. A voltmeter connected in the circuit measures 1.2 V. The internal resistance of each cell is (A) 2.5 ? (B) 4 ? (C) 5? (D) 10 ? Official Ans. by NTA (C) Sol. 1.5V 1.5V r/2 1.5V r 10 ? 20 ? 20 ? r V = E – ir/2 1.2 = 1.5 – i r 2 ?? ?? ?? r i 0.3 2 ? 1.5 ir i 10i 1.5 r 2 10 2 ? ? ? ? ? 10i = 1.5 – 0.3 i = 0.12 A 0.6 r5 0.12 ? ? ? ? 2 4. Identify the pair of physical quantities which have different dimensions : (A) Wave number and Rydberg’s constant (B) Stress and Coefficient of elasticity (C) Coercivity and Magnetisation (D) Specific heat capacity and Latent heat Official Ans. by NTA (D) Sol. ?? ?? QJ S m T Kg C QJ L m Kg ?? 5. A projectile is projected with velocity of 25 m/s at an angle ? ?with the horizontal. After t seconds its inclination with horizontal becomes zero. If R represents horizontal range of the projectile, the value of ? will be : [use g = 10 m/s 2 ] (A) 2 1 1 5t sin 2 4R ? ?? ?? ?? (B) ? ?? ?? ?? 1 2 1 4R sin 2 5t (C) 2 1 4t tan 5R ? ?? ?? ?? (D) 1 2 R cot 20t ? ?? ?? ?? Official Ans. by NTA (D) Sol. 2 V (2sin cos ) R g ?? ? ? ? ? ? ? Vsin gt tV g sin 22 2 g t 2sin cos R. g sin ?? ?? ? 2 2gt tan R ?? 2 20t R ? 2 R cot 20t ?? 6. A block of mass 10 kg starts sliding on a surface with an initial velocity of 9.8 ms -1 . The coefficient of friction between the surface and bock is 0.5. The distance covered by the block before coming to rest is : [use g = 9.8 ms -2 ] (A) 4.9 m (B) 9.8 m (C) 12.5 m (D) 19.6 m Official Ans. by NTA (B) Sol. 2 a g 0.5 9.8 4.9m / s ? ? ? ? ? ? ? ? 2 v 9.8 9.8 d 2a 2(4.9) ? ?? = 9.8 m 7. A boy ties a stone of mass 100 g to the end of a 2 m long string and whirls it around in a horizontal plane. The string can withstand the maximum tension of 80 N. If the maximum speed with which the stone can revolve is K rev. / min ? . The value of K is : (Assume the string is massless and unstretchable) (A) 400 (B) 300 (C) 600 (D) 800 Official Ans. by NTA (C) Sol. T = M ? 2 R T = 80 N M = 0.1 ? = ? R = 2m 80 = 0.1 ? 2 (2) ? 2 = 400 ? = 20 2 ?f = 20 10 rev f s ? ? 600 rev min ? ? Page 3 1 FINAL JEE –MAIN EXAMINATION – JUNE, 2022 (Held On Friday 24 th June, 2022) TIME : 9 : 00 AM to 12 : 00 PM PHYSICS TEST PAPER WITH SOLUTION SECTION-A 1. The bulk modulus of a liquid is 3 × 10 10 Nm -2 . The pressure required to reduce the volume of liquid by 2% is : (A) 3 × 10 8 Nm -2 (B) 9 × 10 8 Nm -2 (C) 6 × 10 8 Nm -2 (D) 12 × 10 8 Nm -2 Official Ans. by NTA (C) Sol. B = 3 × 10 10 V 0.02 V ? ?? ?? ?? ? ? ? ? ? ?? ? ?? ? PV B P B V V v 10 (3 10 )(0.02) ?? 82 6 10 N / m ?? 2. Given below are two statements : One is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A) : In an uniform magnetic field, speed and energy remains the same for a moving charged particle. Reason (R) : Moving charged particle experiences magnetic force perpendicular to its direction of motion. (A) Both (A) and (R) are true and (R) is the correct explanation of (A) (B) Both (A) and (R) are true but (R) is NOT the correct explanation of (A) (C) (A) is true but (R) is false (D) (A) is false but (R) is true. Official Ans. by NTA (A) Sol. F q(v B) ?? Fv ? Work done ?? FS Work done = 0 3. Two identical cells each of emf 1.5 V are connected in parallel across a parallel combination of two resistors each of resistance 20?. A voltmeter connected in the circuit measures 1.2 V. The internal resistance of each cell is (A) 2.5 ? (B) 4 ? (C) 5? (D) 10 ? Official Ans. by NTA (C) Sol. 1.5V 1.5V r/2 1.5V r 10 ? 20 ? 20 ? r V = E – ir/2 1.2 = 1.5 – i r 2 ?? ?? ?? r i 0.3 2 ? 1.5 ir i 10i 1.5 r 2 10 2 ? ? ? ? ? 10i = 1.5 – 0.3 i = 0.12 A 0.6 r5 0.12 ? ? ? ? 2 4. Identify the pair of physical quantities which have different dimensions : (A) Wave number and Rydberg’s constant (B) Stress and Coefficient of elasticity (C) Coercivity and Magnetisation (D) Specific heat capacity and Latent heat Official Ans. by NTA (D) Sol. ?? ?? QJ S m T Kg C QJ L m Kg ?? 5. A projectile is projected with velocity of 25 m/s at an angle ? ?with the horizontal. After t seconds its inclination with horizontal becomes zero. If R represents horizontal range of the projectile, the value of ? will be : [use g = 10 m/s 2 ] (A) 2 1 1 5t sin 2 4R ? ?? ?? ?? (B) ? ?? ?? ?? 1 2 1 4R sin 2 5t (C) 2 1 4t tan 5R ? ?? ?? ?? (D) 1 2 R cot 20t ? ?? ?? ?? Official Ans. by NTA (D) Sol. 2 V (2sin cos ) R g ?? ? ? ? ? ? ? Vsin gt tV g sin 22 2 g t 2sin cos R. g sin ?? ?? ? 2 2gt tan R ?? 2 20t R ? 2 R cot 20t ?? 6. A block of mass 10 kg starts sliding on a surface with an initial velocity of 9.8 ms -1 . The coefficient of friction between the surface and bock is 0.5. The distance covered by the block before coming to rest is : [use g = 9.8 ms -2 ] (A) 4.9 m (B) 9.8 m (C) 12.5 m (D) 19.6 m Official Ans. by NTA (B) Sol. 2 a g 0.5 9.8 4.9m / s ? ? ? ? ? ? ? ? 2 v 9.8 9.8 d 2a 2(4.9) ? ?? = 9.8 m 7. A boy ties a stone of mass 100 g to the end of a 2 m long string and whirls it around in a horizontal plane. The string can withstand the maximum tension of 80 N. If the maximum speed with which the stone can revolve is K rev. / min ? . The value of K is : (Assume the string is massless and unstretchable) (A) 400 (B) 300 (C) 600 (D) 800 Official Ans. by NTA (C) Sol. T = M ? 2 R T = 80 N M = 0.1 ? = ? R = 2m 80 = 0.1 ? 2 (2) ? 2 = 400 ? = 20 2 ?f = 20 10 rev f s ? ? 600 rev min ? ? 3 8. A vertical electric field of magnitude 4.9 × 10 5 N/C just prevents a water droplet of a mass 0.1 g from falling. The value of charge on the droplet will be : (Given g = 9.8 m/s 2 ) (A) 1.6 × 10 -9 C (B) 2.0 × 10 -9 C (C) 3.2 × 10 -9 C (D) 0.5 × 10 -9 C Official Ans. by NTA (B) Sol. Mg = qE 35 (0.1 10 )(9.8) 4.9 10 q ? ? ? ? 4 5 2 10 q 10 ? ? ? 9 q 2 10 C ? ?? 9. A particle experiences a variable force 2 ˆˆ F (4xi 3y j) ?? in a horizontal x-y plane. Assume distance in meters and force is newton. If the particle moves from point (1, 2) to point (2, 3) in the x-y plane, the Kinetic Energy changes by (A) 50.0 J (B) 12.5 J (C) 25.0 J (D) 0 J Official Ans. by NTA (C) Sol. 2 ˆˆ F 4xi 3y j ?? WD = ?KE ˆˆ W F.(dxi dyj) ?? ? 23 2 12 4xdx 3y dx ?? ?? 2 2 3 3 12 (2x ) (y ) ?? (8 2) (27 8) ? ? ? ? 6 19 25J ? ? ? 10. The approximate height from the surface of earth at which the weight of the body becomes 1 3 of its weight on the surface of earth is : [Radius of earth R = 6400 km and 3 1.732 ? ] (A) 3840 km (B) 4685 km (C) 2133 km (D) 4267 km Official Ans. by NTA (B) Sol. M Mg' g 3 ? g g' 3 ? 2 Rg g' g R h 3 ?? ?? ?? ? ?? R1 . Rh 3 ? ? h ( 3 1)R ?? (1.732 1)6400 ?? h 4685km ? 11. A resistance of 40 ? is connected to a source of alternating current rated 220 V, 50 Hz. Find the time taken by the current to change from its maximum value to rms value : (A) 2.5 ms (B) 1.25 ms (C) 2.5 s (D) 0.25 s Official Ans. by NTA (A) Sol. Considering sinusoidal AC. Phase at maximum value ? ? 2 Phase at rms value = ? 3 4 Thus phase change ? ? ? ? ? ? 3 4 2 4 Now ? = 2 ?f = 2 ? × 50 = 100 ? time taken t = ?? ?? ?? / 4 1 s 100 400 t = 2.5 × 10 –3 = 2.5 ms Page 4 1 FINAL JEE –MAIN EXAMINATION – JUNE, 2022 (Held On Friday 24 th June, 2022) TIME : 9 : 00 AM to 12 : 00 PM PHYSICS TEST PAPER WITH SOLUTION SECTION-A 1. The bulk modulus of a liquid is 3 × 10 10 Nm -2 . The pressure required to reduce the volume of liquid by 2% is : (A) 3 × 10 8 Nm -2 (B) 9 × 10 8 Nm -2 (C) 6 × 10 8 Nm -2 (D) 12 × 10 8 Nm -2 Official Ans. by NTA (C) Sol. B = 3 × 10 10 V 0.02 V ? ?? ?? ?? ? ? ? ? ? ?? ? ?? ? PV B P B V V v 10 (3 10 )(0.02) ?? 82 6 10 N / m ?? 2. Given below are two statements : One is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A) : In an uniform magnetic field, speed and energy remains the same for a moving charged particle. Reason (R) : Moving charged particle experiences magnetic force perpendicular to its direction of motion. (A) Both (A) and (R) are true and (R) is the correct explanation of (A) (B) Both (A) and (R) are true but (R) is NOT the correct explanation of (A) (C) (A) is true but (R) is false (D) (A) is false but (R) is true. Official Ans. by NTA (A) Sol. F q(v B) ?? Fv ? Work done ?? FS Work done = 0 3. Two identical cells each of emf 1.5 V are connected in parallel across a parallel combination of two resistors each of resistance 20?. A voltmeter connected in the circuit measures 1.2 V. The internal resistance of each cell is (A) 2.5 ? (B) 4 ? (C) 5? (D) 10 ? Official Ans. by NTA (C) Sol. 1.5V 1.5V r/2 1.5V r 10 ? 20 ? 20 ? r V = E – ir/2 1.2 = 1.5 – i r 2 ?? ?? ?? r i 0.3 2 ? 1.5 ir i 10i 1.5 r 2 10 2 ? ? ? ? ? 10i = 1.5 – 0.3 i = 0.12 A 0.6 r5 0.12 ? ? ? ? 2 4. Identify the pair of physical quantities which have different dimensions : (A) Wave number and Rydberg’s constant (B) Stress and Coefficient of elasticity (C) Coercivity and Magnetisation (D) Specific heat capacity and Latent heat Official Ans. by NTA (D) Sol. ?? ?? QJ S m T Kg C QJ L m Kg ?? 5. A projectile is projected with velocity of 25 m/s at an angle ? ?with the horizontal. After t seconds its inclination with horizontal becomes zero. If R represents horizontal range of the projectile, the value of ? will be : [use g = 10 m/s 2 ] (A) 2 1 1 5t sin 2 4R ? ?? ?? ?? (B) ? ?? ?? ?? 1 2 1 4R sin 2 5t (C) 2 1 4t tan 5R ? ?? ?? ?? (D) 1 2 R cot 20t ? ?? ?? ?? Official Ans. by NTA (D) Sol. 2 V (2sin cos ) R g ?? ? ? ? ? ? ? Vsin gt tV g sin 22 2 g t 2sin cos R. g sin ?? ?? ? 2 2gt tan R ?? 2 20t R ? 2 R cot 20t ?? 6. A block of mass 10 kg starts sliding on a surface with an initial velocity of 9.8 ms -1 . The coefficient of friction between the surface and bock is 0.5. The distance covered by the block before coming to rest is : [use g = 9.8 ms -2 ] (A) 4.9 m (B) 9.8 m (C) 12.5 m (D) 19.6 m Official Ans. by NTA (B) Sol. 2 a g 0.5 9.8 4.9m / s ? ? ? ? ? ? ? ? 2 v 9.8 9.8 d 2a 2(4.9) ? ?? = 9.8 m 7. A boy ties a stone of mass 100 g to the end of a 2 m long string and whirls it around in a horizontal plane. The string can withstand the maximum tension of 80 N. If the maximum speed with which the stone can revolve is K rev. / min ? . The value of K is : (Assume the string is massless and unstretchable) (A) 400 (B) 300 (C) 600 (D) 800 Official Ans. by NTA (C) Sol. T = M ? 2 R T = 80 N M = 0.1 ? = ? R = 2m 80 = 0.1 ? 2 (2) ? 2 = 400 ? = 20 2 ?f = 20 10 rev f s ? ? 600 rev min ? ? 3 8. A vertical electric field of magnitude 4.9 × 10 5 N/C just prevents a water droplet of a mass 0.1 g from falling. The value of charge on the droplet will be : (Given g = 9.8 m/s 2 ) (A) 1.6 × 10 -9 C (B) 2.0 × 10 -9 C (C) 3.2 × 10 -9 C (D) 0.5 × 10 -9 C Official Ans. by NTA (B) Sol. Mg = qE 35 (0.1 10 )(9.8) 4.9 10 q ? ? ? ? 4 5 2 10 q 10 ? ? ? 9 q 2 10 C ? ?? 9. A particle experiences a variable force 2 ˆˆ F (4xi 3y j) ?? in a horizontal x-y plane. Assume distance in meters and force is newton. If the particle moves from point (1, 2) to point (2, 3) in the x-y plane, the Kinetic Energy changes by (A) 50.0 J (B) 12.5 J (C) 25.0 J (D) 0 J Official Ans. by NTA (C) Sol. 2 ˆˆ F 4xi 3y j ?? WD = ?KE ˆˆ W F.(dxi dyj) ?? ? 23 2 12 4xdx 3y dx ?? ?? 2 2 3 3 12 (2x ) (y ) ?? (8 2) (27 8) ? ? ? ? 6 19 25J ? ? ? 10. The approximate height from the surface of earth at which the weight of the body becomes 1 3 of its weight on the surface of earth is : [Radius of earth R = 6400 km and 3 1.732 ? ] (A) 3840 km (B) 4685 km (C) 2133 km (D) 4267 km Official Ans. by NTA (B) Sol. M Mg' g 3 ? g g' 3 ? 2 Rg g' g R h 3 ?? ?? ?? ? ?? R1 . Rh 3 ? ? h ( 3 1)R ?? (1.732 1)6400 ?? h 4685km ? 11. A resistance of 40 ? is connected to a source of alternating current rated 220 V, 50 Hz. Find the time taken by the current to change from its maximum value to rms value : (A) 2.5 ms (B) 1.25 ms (C) 2.5 s (D) 0.25 s Official Ans. by NTA (A) Sol. Considering sinusoidal AC. Phase at maximum value ? ? 2 Phase at rms value = ? 3 4 Thus phase change ? ? ? ? ? ? 3 4 2 4 Now ? = 2 ?f = 2 ? × 50 = 100 ? time taken t = ?? ?? ?? / 4 1 s 100 400 t = 2.5 × 10 –3 = 2.5 ms 4 12. The equations of two waves are given by : 1 y 5sin2 (x vt)cm ? ? ? 2 y 3sin2 (x vt 1.5)cm ? ? ? ? These waves are simultaneously passing through a string. The amplitude of the resulting wave is (A) 2 cm (B) 4 cm (C) 5.8 cm (D) 8 cm Official Ans. by NTA (A) Sol. 12 A 5 A 3 ?? 2 (1.5) 3 ? ? ? ? ? ? 22 net 1 2 1 2 A A A 2A A cos(3 ) ? ? ? ? 12 AA ?? = 2cm 13. A plane electromagnetic wave travels in a medium of relative permeability 1.61 and relative permittivity 6.44. If magnitude of magnetic intensity is 4.5 × 10 -2 Am -1 at a point, what will be the approximate magnitude of electric field intensity at that point ? (Given : permeability of free space ? 0 = 4 ? × 10 -7 NA -2 , speed of light in vacuum c = 3 × 10 8 ms -1 ) (A) 16.96 Vm -1 (B) 2.25 × 10 -2 Vm -1 (C) 8.48 Vm -1 (D) 6.75 × 10 6 Vm -1 Official Ans. by NTA (C) Sol. r 1.61 ?? r 6.44 ?? 2 B 4.5 10 ? ?? E = ? 00 11 CV ?? ? ? ? ? rr C 1.61 6.44 V ? ? ? ? ? 8 7 3 10 V 9.32 10 m / s B 1.61 6.44 ?? ? ? ? ? ? 27 E 4.5 10 9.32 10 ? ? ? ? ? 6 4.2 10 ?? 14. Choose the correct option from the following options given below : (A) In the ground state of Rutherford's model electrons are in stable equilibrium. While in Thomson's model electrons always experience a net-force. (B) An atom has a nearly continuous mass distribution in a Rutherford's model but has a highly non-uniform mass distribution in Thomson's model (C) A classical atom based on Rutherford's model is doomed to collapse. (D) The positively charged part of the atom possesses most of the mass in Rutherford's model but not in Thomson's model. Official Ans. by NTA (C) Sol. According to Rutherford, e – revolves around nucleus in circular orbit. Thus e – is always accelerating (centripetal acceleration). An accelerating change emits EM radiation and thus e – should loose energy and finally should collapse in the nucleus. 15. Nucleus A is having mass number 220 and its binding energy per nucleon is 5.6 MeV. It splits in two fragments 'B' and 'C' of mass numbers 105 and 115. The binding energy of nucleons in 'B' and 'C' is 6.4 MeV per nucleon. The energy Q released per fission will be : (A) 0.8 MeV (B) 275 MeV (C) 220 MeV (D) 176 MeV Official Ans. by NTA (D) Sol. PR Q (B.E) (B.E) ?? (105 115)(6.4) (220)(5.6) ? ? ? = 176 MeV 16. A baseband signal of 3.5 MHz frequency is modulated with a carrier signal of 3.5 GHz frequency using amplitude modulation method. What should be the minimum size of antenna required to transmit the modulated signal ? (A) 42.8 m (B) 42.8 mm (C) 21.4 mm (D) 21.4 m Official Ans. by NTA (C) Page 5 1 FINAL JEE –MAIN EXAMINATION – JUNE, 2022 (Held On Friday 24 th June, 2022) TIME : 9 : 00 AM to 12 : 00 PM PHYSICS TEST PAPER WITH SOLUTION SECTION-A 1. The bulk modulus of a liquid is 3 × 10 10 Nm -2 . The pressure required to reduce the volume of liquid by 2% is : (A) 3 × 10 8 Nm -2 (B) 9 × 10 8 Nm -2 (C) 6 × 10 8 Nm -2 (D) 12 × 10 8 Nm -2 Official Ans. by NTA (C) Sol. B = 3 × 10 10 V 0.02 V ? ?? ?? ?? ? ? ? ? ? ?? ? ?? ? PV B P B V V v 10 (3 10 )(0.02) ?? 82 6 10 N / m ?? 2. Given below are two statements : One is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A) : In an uniform magnetic field, speed and energy remains the same for a moving charged particle. Reason (R) : Moving charged particle experiences magnetic force perpendicular to its direction of motion. (A) Both (A) and (R) are true and (R) is the correct explanation of (A) (B) Both (A) and (R) are true but (R) is NOT the correct explanation of (A) (C) (A) is true but (R) is false (D) (A) is false but (R) is true. Official Ans. by NTA (A) Sol. F q(v B) ?? Fv ? Work done ?? FS Work done = 0 3. Two identical cells each of emf 1.5 V are connected in parallel across a parallel combination of two resistors each of resistance 20?. A voltmeter connected in the circuit measures 1.2 V. The internal resistance of each cell is (A) 2.5 ? (B) 4 ? (C) 5? (D) 10 ? Official Ans. by NTA (C) Sol. 1.5V 1.5V r/2 1.5V r 10 ? 20 ? 20 ? r V = E – ir/2 1.2 = 1.5 – i r 2 ?? ?? ?? r i 0.3 2 ? 1.5 ir i 10i 1.5 r 2 10 2 ? ? ? ? ? 10i = 1.5 – 0.3 i = 0.12 A 0.6 r5 0.12 ? ? ? ? 2 4. Identify the pair of physical quantities which have different dimensions : (A) Wave number and Rydberg’s constant (B) Stress and Coefficient of elasticity (C) Coercivity and Magnetisation (D) Specific heat capacity and Latent heat Official Ans. by NTA (D) Sol. ?? ?? QJ S m T Kg C QJ L m Kg ?? 5. A projectile is projected with velocity of 25 m/s at an angle ? ?with the horizontal. After t seconds its inclination with horizontal becomes zero. If R represents horizontal range of the projectile, the value of ? will be : [use g = 10 m/s 2 ] (A) 2 1 1 5t sin 2 4R ? ?? ?? ?? (B) ? ?? ?? ?? 1 2 1 4R sin 2 5t (C) 2 1 4t tan 5R ? ?? ?? ?? (D) 1 2 R cot 20t ? ?? ?? ?? Official Ans. by NTA (D) Sol. 2 V (2sin cos ) R g ?? ? ? ? ? ? ? Vsin gt tV g sin 22 2 g t 2sin cos R. g sin ?? ?? ? 2 2gt tan R ?? 2 20t R ? 2 R cot 20t ?? 6. A block of mass 10 kg starts sliding on a surface with an initial velocity of 9.8 ms -1 . The coefficient of friction between the surface and bock is 0.5. The distance covered by the block before coming to rest is : [use g = 9.8 ms -2 ] (A) 4.9 m (B) 9.8 m (C) 12.5 m (D) 19.6 m Official Ans. by NTA (B) Sol. 2 a g 0.5 9.8 4.9m / s ? ? ? ? ? ? ? ? 2 v 9.8 9.8 d 2a 2(4.9) ? ?? = 9.8 m 7. A boy ties a stone of mass 100 g to the end of a 2 m long string and whirls it around in a horizontal plane. The string can withstand the maximum tension of 80 N. If the maximum speed with which the stone can revolve is K rev. / min ? . The value of K is : (Assume the string is massless and unstretchable) (A) 400 (B) 300 (C) 600 (D) 800 Official Ans. by NTA (C) Sol. T = M ? 2 R T = 80 N M = 0.1 ? = ? R = 2m 80 = 0.1 ? 2 (2) ? 2 = 400 ? = 20 2 ?f = 20 10 rev f s ? ? 600 rev min ? ? 3 8. A vertical electric field of magnitude 4.9 × 10 5 N/C just prevents a water droplet of a mass 0.1 g from falling. The value of charge on the droplet will be : (Given g = 9.8 m/s 2 ) (A) 1.6 × 10 -9 C (B) 2.0 × 10 -9 C (C) 3.2 × 10 -9 C (D) 0.5 × 10 -9 C Official Ans. by NTA (B) Sol. Mg = qE 35 (0.1 10 )(9.8) 4.9 10 q ? ? ? ? 4 5 2 10 q 10 ? ? ? 9 q 2 10 C ? ?? 9. A particle experiences a variable force 2 ˆˆ F (4xi 3y j) ?? in a horizontal x-y plane. Assume distance in meters and force is newton. If the particle moves from point (1, 2) to point (2, 3) in the x-y plane, the Kinetic Energy changes by (A) 50.0 J (B) 12.5 J (C) 25.0 J (D) 0 J Official Ans. by NTA (C) Sol. 2 ˆˆ F 4xi 3y j ?? WD = ?KE ˆˆ W F.(dxi dyj) ?? ? 23 2 12 4xdx 3y dx ?? ?? 2 2 3 3 12 (2x ) (y ) ?? (8 2) (27 8) ? ? ? ? 6 19 25J ? ? ? 10. The approximate height from the surface of earth at which the weight of the body becomes 1 3 of its weight on the surface of earth is : [Radius of earth R = 6400 km and 3 1.732 ? ] (A) 3840 km (B) 4685 km (C) 2133 km (D) 4267 km Official Ans. by NTA (B) Sol. M Mg' g 3 ? g g' 3 ? 2 Rg g' g R h 3 ?? ?? ?? ? ?? R1 . Rh 3 ? ? h ( 3 1)R ?? (1.732 1)6400 ?? h 4685km ? 11. A resistance of 40 ? is connected to a source of alternating current rated 220 V, 50 Hz. Find the time taken by the current to change from its maximum value to rms value : (A) 2.5 ms (B) 1.25 ms (C) 2.5 s (D) 0.25 s Official Ans. by NTA (A) Sol. Considering sinusoidal AC. Phase at maximum value ? ? 2 Phase at rms value = ? 3 4 Thus phase change ? ? ? ? ? ? 3 4 2 4 Now ? = 2 ?f = 2 ? × 50 = 100 ? time taken t = ?? ?? ?? / 4 1 s 100 400 t = 2.5 × 10 –3 = 2.5 ms 4 12. The equations of two waves are given by : 1 y 5sin2 (x vt)cm ? ? ? 2 y 3sin2 (x vt 1.5)cm ? ? ? ? These waves are simultaneously passing through a string. The amplitude of the resulting wave is (A) 2 cm (B) 4 cm (C) 5.8 cm (D) 8 cm Official Ans. by NTA (A) Sol. 12 A 5 A 3 ?? 2 (1.5) 3 ? ? ? ? ? ? 22 net 1 2 1 2 A A A 2A A cos(3 ) ? ? ? ? 12 AA ?? = 2cm 13. A plane electromagnetic wave travels in a medium of relative permeability 1.61 and relative permittivity 6.44. If magnitude of magnetic intensity is 4.5 × 10 -2 Am -1 at a point, what will be the approximate magnitude of electric field intensity at that point ? (Given : permeability of free space ? 0 = 4 ? × 10 -7 NA -2 , speed of light in vacuum c = 3 × 10 8 ms -1 ) (A) 16.96 Vm -1 (B) 2.25 × 10 -2 Vm -1 (C) 8.48 Vm -1 (D) 6.75 × 10 6 Vm -1 Official Ans. by NTA (C) Sol. r 1.61 ?? r 6.44 ?? 2 B 4.5 10 ? ?? E = ? 00 11 CV ?? ? ? ? ? rr C 1.61 6.44 V ? ? ? ? ? 8 7 3 10 V 9.32 10 m / s B 1.61 6.44 ?? ? ? ? ? ? 27 E 4.5 10 9.32 10 ? ? ? ? ? 6 4.2 10 ?? 14. Choose the correct option from the following options given below : (A) In the ground state of Rutherford's model electrons are in stable equilibrium. While in Thomson's model electrons always experience a net-force. (B) An atom has a nearly continuous mass distribution in a Rutherford's model but has a highly non-uniform mass distribution in Thomson's model (C) A classical atom based on Rutherford's model is doomed to collapse. (D) The positively charged part of the atom possesses most of the mass in Rutherford's model but not in Thomson's model. Official Ans. by NTA (C) Sol. According to Rutherford, e – revolves around nucleus in circular orbit. Thus e – is always accelerating (centripetal acceleration). An accelerating change emits EM radiation and thus e – should loose energy and finally should collapse in the nucleus. 15. Nucleus A is having mass number 220 and its binding energy per nucleon is 5.6 MeV. It splits in two fragments 'B' and 'C' of mass numbers 105 and 115. The binding energy of nucleons in 'B' and 'C' is 6.4 MeV per nucleon. The energy Q released per fission will be : (A) 0.8 MeV (B) 275 MeV (C) 220 MeV (D) 176 MeV Official Ans. by NTA (D) Sol. PR Q (B.E) (B.E) ?? (105 115)(6.4) (220)(5.6) ? ? ? = 176 MeV 16. A baseband signal of 3.5 MHz frequency is modulated with a carrier signal of 3.5 GHz frequency using amplitude modulation method. What should be the minimum size of antenna required to transmit the modulated signal ? (A) 42.8 m (B) 42.8 mm (C) 21.4 mm (D) 21.4 m Official Ans. by NTA (C) 5 Sol. cm f 3.5GHz f 3.5MHz ?? Side band frequencies are f c – f m & f c + f m . which are almost f c c c f ?? Minimum length of antenna = 8 9 c c 3 10 f 4 4 3.5 10 4 ?? ?? ?? = 21.4 mm 17. A Carnot engine whose heat sinks at 27°C, has an efficiency of 25%. By how many degrees should the temperature of the source be changed to increase the efficiency by 100% of the original efficiency ? (A) Increases by 18°C (B) Increase by 200°C (C) Increase by 120°C (D) Increase by 73° Official Ans. by NTA (B) Sol. Source T T=273+ 27 =300K n=25% 300 1 0.25 T ?? 300 0.75 T ? T = 400K If efficiency increased by 100% then new efficiency ? n’ = 50% 300 1 0.5 T' ?? T' 600K ? Increase in temp = 600 – 400 = 200 K or 200°C 18. A parallel plate capacitor is formed by two plates each of area 30 ? ?cm 2 separated by 1 mm. A material of dielectric strength 3.6 × 10 7 Vm -1 is filled between the plates. If the maximum charge that can be stored on the capacitor without causing any dielectric breakdown is 7 × 10 -6 C, the value of dielectric constant of the material is : ? ?? ?? ?? ?? ?? ?? ?? 9 2 2 0 1 Use : 9 10 Nm C 4 (A) 1.66 (B) 1.75 (C) 2.25 (D) 2.33 Official Ans. by NTA (D) Sol. 6 47 0 9 q 7 10 K 1 AE 30 10 3.6 10 4 9 10 ? ? ? ?? ? ? ? ? ? ? ? ? ? 36 7 K 2.33 30 3.6 ? ?? ? 19. The magnetic field at the centre of a circular coil of radius r, due to current I flowing through it, is B. The magnetic field at a point along the axis at a distance r 2 from the centre is : (A) B/2 (B) 2B (C) 3 2 B 5 ?? ?? ?? (D) 3 2 B 3 ?? ?? ?? Official Ans. by NTA (C) Sol. 2 00 Ca 2 2 3/2 I Ir B ,B 2r 2(x r ) ?? ?? ? At r x 2 ? 2 0 a 3/2 2 2 Ir B r 2r 4 ? ? ?? ? ?? ?? 3/2 2 00 3/2 2 Ir I 4 2r 5 5 2r 4 ?? ?? ?? ?? ?? ?? ?? ?? 3 0 I 2 2r 5 ? ?? ? ?? ??Read More
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