Practice Questions

Q30.Match List I with List II LIST I LIST II A AM Broadcast I 88 −108 MHz B FM Broadcast II 540 −1600 kHz C Television III 3. 7 −4. 2 GHz D Satellite Communication IV 54 MHz − 590 MHz Choose the correct answer from the options given below: (1) A-II, B-I, C-IV, D-III (2) A-IV, B-III, C-I, D-II (3) A-II, B-III, C-I, D-IV (4) A-I, B-III, C-II, D-IV

Q30.Match List I with List II List I List II AAttenuation I Combination of a receiver and transmitter Process of retrieval of information from the carrier wave at B Transducer II receiver C DemodulationIII Converts one form of energy into another of strength of a signal while propagating through a DRepeater IVLoss medium JEE Main 2023 (30 Jan Shift 2) JEE Main Previous Year Paper Choose the correct answer from the options given below : (1) A-I, B-II, C-III, D-IV (2) A-II, B-III, C-IV, D-I (3) A-IV, B-III, C-I, D-II (4) A-IV, B-III, C-II, D-I

Q30.An atom absorbs a photon of wavelength 500 nm and emits another photon of wavelength 600 nm. The net energy absorbed by the atom in this process is 𝑛× 10-4eV. The value of 𝑛 is [Assume the atom to be JEE Main 2023 (13 Apr Shift 2) JEE Main Previous Year Paper stationary during the absorption and emission process] (Take ℎ= 6 . 6 × 10-34J s and 𝑐= 3 × 108 m s-1 ). Q31.. Identify the correct order of standard enthalpy of formation of sodium halides. (1) NaI < NaBr < NaF < NaCl (2) NaI < NaBr < NaCl < NaF (3) NaF < NaCl < NaBr < NaI (4) NaCl < NaF < NaBr < NaI

Q30.For an amplitude modulated wave the minimum amplitude is 3 V , while the modulation index is 60%. The maximum amplitude of the modulated wave is: (1) 5 V (2) 15 V (3) 12 V (4) 10 V

Q30.The radius of fifth orbit of Li+ + is_______ × 10-12 m . Take: radius of hydrogen atom = 0 . 51 A

Q30.Match List-I with List-II List-I List-II (Layer of atmosphere) (Approximate height over earth's surface) (A) F1−Layer (I) 10 km (B) D−Layer (II) 170 −190 km (C) Troposphere (III) 100 km (D) E−Layer (V) 65 −75 km Choose the correct answer from the options given below. (1) A– II, B– IV, C–I, D– III (2) A– II, B– IV, C– III, D–I (3) A– III, B– IV, C–I, D– II (4) A– II, B–I, C– IV, D– III

Q30.In an amplitude modulation, a modulating signal having amplitude of X V is superimposed with a carrier signal of amplitude Y V in first case. Then, in second case, the same modulating signal is superimposed with different carrier signal of amplitude 2Y V. The ratio of modulation index in the two case respectively wil be : (1) 1 : 2 (2) 1 : 1 (3) 2 : 1 (4) 4 : 1

Q1. Identify the pair of physical quantities that have same dimensions: (1) Velocity gradient and decay constant (2) Angular frequency and angular momentum (3) Wave number and Avogadro number (4) Wein's constant and Stephan's constant

Q1. Two projectile thrown at 30° and 45° with the horizontal respectively, reach the maximum height in same time. The ratio of their initial velocities is (1) 1 : √2 (2) 2 : 1 (3) √2 : 1 (4) 1 : 2

Q1. Match List I with List II. List I List II (A) Torque (I) Nms-1 (B) Stress (II) Jkg-1 (C) Latent Heat (III) Nm (D) Power (IV) Nm-2 Choose the correct answer from the options given below: (1) A - III, B - II, C - I, D - IV (2) A - III, B - IV, C - II, D - I (3) A - IV, B - I, C - III, D - II (4) A - II, B - III, C - I, D - IV

Q1. If 𝑍= 𝐴2𝐵3 , then the relative error in 𝑍 will be 𝐶4 2𝛥𝐴 3𝛥𝐵 4𝛥𝐶 𝛥𝐴 𝛥𝐵 𝛥𝐶 (1) 𝐴+ 𝐵+ 𝐶 (2) 𝐴+ 𝐵+ 𝐶 (3) 2𝛥𝐴 3𝛥𝐵 4𝛥𝐶 (4) 𝛥𝐴 𝛥𝐵 𝛥𝐶 𝐴+ 𝐵- 𝐶 𝐴+ 𝐵- 𝐶 Q2. →𝐴 is a vector quantity such that →𝐴= non-zero constant. Which of the following expression is true for →𝐴? (1) →𝐴· →𝐴= 0 (2) →𝐴× →𝐴< 0 (3) →𝐴× →𝐴= 0 (4) →𝐴× →𝐴> 0

Q1. Two buses 𝑃 and 𝑄 start from a point at the same time and move in a straight line and their positions are represented by 𝑥𝑃𝑡= 𝛼𝑡+ 𝛽𝑡2 and 𝑥𝑄𝑡= 𝑓𝑡- 𝑡2. At what time, both the buses have same velocity ? (1) 𝛼- 𝑓 (2) 𝛼+ 𝑓 1 + 𝛽 2𝛽- 1 (3) 𝛼+ 𝑓 (4) 𝑓- 𝛼 21 + 𝛽 21 + 𝛽

Q1. The dimension of mutual inductance is (1) ML2 T−2A−1 (2) ML2 T−2A−2 (3) ML2 T−3A−1 (4) ML2 T−3A−2

Q1. The distance of the Sun from earth is 1. 5 × 1011 m and its angular diameter is 2000′′ when observed from the earth. The diameter of the Sun will be (1) 2. 45 × 1010 m (2) 1. 45 × 1010 m (3) 1. 45 × 109 m (4) 0. 14 × 109 m

Q1. The maximum error in the measurement of resistance, current and time for which current flows in an electrical circuit are 1%, 2% and 3% respectively. The maximum percentage error in the detection of the dissipated heat will be: (1) 2 (2) 4 (3) 6 (4) 8

Q1. Two projectiles are thrown with same initial velocity making an angle of 45° and 30° with the horizontal respectively. The ratio of their respective ranges will be (1) 1: √2 (2) √2: 1 (3) 2: √3 (4) √3: 2

Q2. Motion of a particle in x −y plane is described by a set of following equations x = 4 sin( π2 −ωt) m and y = 4 sin(ωt) m. The path of the particle will be (1) circular (2) helical (3) parabolic (4) eliptical

Q2. At time t = 0 a particle starts travelling from a height 7ˆz cm in a plane keeping z coordinate constant. At any instant of time, it's position along the x and y directions are defined as 3t and 5t3 respectively. At t = 1 s acceleration of the particle will be (1) −30y (2) 30y (3) 3x + 15y (4) 3x + 15y + 7ˆz

Q2. A person is standing in an elevator. In which situation, he experiences weight loss ? (1) When the elevator moves upward with constant (2) When the elevator moves downward with acceleration constant acceleration (3) When the elevator moves upward with uniform (4) When the elevator moves downward with uniform velocity velocity

Q2. A person can throw a ball upto a maximum range of 100 m . How high above the ground he can throw the same ball? (1) 25 m (2) 50 m (3) 100 m (4) 200 m

Q2. A ball is projected from the ground with a speed 15 m s−1 at an angle θ with horizontal so that its range and maximum height are equal, then tan θ will be equal to (1) 1 (2) 1 4 2 (3) 2 (4) 4

Q2. The SI unit of a physical quantity is Pascal ‐ sec. The dimensional formula of this quantity will be (1) ML2T −1 (2) M −1L3T 0 (3) ML−1T −1 (4) ML−1T −2

Q2. A NCC parade is going at a uniform speed of 9 km h-1 under a mango tree on which a monkey is sitting at a height of 19 . 6 m. At any particular instant, the monkey drops a mango. A cadet will receive the mango whose distance from the tree at time of drop is : (Given 𝑔= 9 . 8 m s-2) (1) 5 m (2) 10 m (3) 19 . 8 m (4) 24 . 5 m

Q3. If t = √x + 4, then ( dxdt )t=4 is: (1) 4 (2) Zero (3) 8 (4) 16

Q3. An object is thrown vertically upwards. At its maximum height, which of the following quantity becomes zero ? (1) Momentum (2) Potential energy (3) Acceleration (4) Force