Practice Questions

Q25.When one light ray is reflected from a plane mirror with 30° angle of reflection, the angle of deviation of the ray after reflection is: JEE Main 2023 (11 Apr Shift 2) JEE Main Previous Year Paper (1) 120° (2) 110° (3) 140° (4) 130°

Q26.Electron beam used in an electron microscope, when accelerated by a voltage of 20 kV has a de-Broglie wavelength of λ0 . If the voltage is increased to 40 kV then the de-Broglie wavelength associated with the electron beam would be: (1) 3λ0 (2) 9λ0 (3) λ0 (4) λ0 2 √2

Q26.The light rays from an object have been reflected towards an observer from a standard flat mirror, the image observed by the observer are :- A. Real B. Erect C. Smaller in size than object D. Laterally inverted Choose the most appropriate answer from the options given below: (1) B and D only (2) B and C only (3) A and D only (4) A, C and D only

Q26.Proton (P) and electron (e) will have same de-Broglie wavelength when the ratio of their momentum is (assume, mp = 1849 me ) (1) 1 : 1 (2) 1 : 1849 (3) 1 : 43 (4) 43 : 1

Q26.If a radioactive element having half-life of 30 min is undergoing beta decay, the fraction of radioactive element remains undecayed after 90 min will be : (1) 1 (2) 1 8 16 (3) 1 (4) 1 4 2

Q27.The radius of electron's second stationary orbit in Bohr's atom is R. The radius of 3rd orbit will be (1) R (2) 2. 25 R 3 (3) 3R (4) 9R

Q27.An electron of a hydrogen like atom, having Z = 4 , jumps from 4th energy state to 2nd energy state, The energy released in this process, will be: (Given Rch = 13. 6 eV ) Where R = Rydberg constant c = Speed of light in vacuum h = Planck's constant (1) 13. 6 eV (2) 10. 5 eV (3) 3. 4 eV (4) 40. 8 eV

Q28.The ratio of the density of oxygen nucleus (168O) and helium nucleus (42He) is (1) 4 : 1 (2) 8 : 1 (3) 1 : 1 (4) 2 : 1

Q28.Which of the following statement is not correct in the case of light emitting diodes? A. It is a heavily doped p-n junction. B. It emits light only when it is forward biased. C. It emits light only when it is reverse biased. D. The energy of the light emitted is equal to or slightly less than the energy gap of the semiconductor used. Choose the correct answer from the options given below : (1) C and D (2) A (3) C (4) B

Q28.The energy of He+ ion in its first state is, (The ground state energy for the Hydrogen atom −13. 6 eV): (1) −27. 2 eV (2) −3. 4 eV (3) −13. 6 eV (4) −54. 4 eV

Q28.For the following circuit and given inputs A and B, choose the correct option for output ‵Y ′ JEE Main 2023 (13 Apr Shift 1) JEE Main Previous Year Paper (1) (2) (3) (4)

Q28.For the given logic gates combination, the correct truth table will be (1) A B X (2) A B X 0 0 1 0 0 0 0 1 0 0 1 1 1 0 0 1 0 1 1 1 0 1 1 0 (3) A B X (4) A B X 0 0 1 0 0 0 0 1 0 0 1 1 1 0 1 1 0 1 1 1 0 1 1 1

Q28.The work functions of Aluminium and Gold are 4. 1 eV and 5. 1 eV respectively. The ratio of the slope of the stopping potential versus frequency plot for Gold to that of Aluminium is (1) 1. 24 (2) 2 (3) 1 (4) 1. 5

Q29.The modulation index for an A.M. wave having maximum and minimum peak to peak voltages of 14 mV and 6 mV respectively is : (1) 1. 4 (2) 0. 4 (3) 0. 2 (4) 0. 6

Q29.Choose the correct statement about Zener diode: (1) It works as a voltage regulator in reverse bias and (2) It works as a voltage regulator in both forward behaves like simple p-n junction diode in forward and reverse bias bias (3) It works a voltage regulator only in forward bias (4) It works as a voltage regulator in forward bias and behaves like simple p-n junction diode in reverse bias

Q29.If the height of transmitting and receiving antennas are 80 m each, the maximum line of sight distance will be : Given : Earth’s radius = 6. 4 × 106 m . (1) 32 km (2) 28 km (3) 36 km (4) 64 km

Q29.In an n-p-n common emitter (CE) transistor the collector current changes from 5 mA to 16 mA for the change in base current from 100 μA and 200 μA, respectively. The current gain of transistor is _____. (1) 110 (2) 210 (3) 0. 9 (4) 9

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.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.A message signal of frequency 5 kHz is used to modulate a carrier signal of frequency 2 MHz . The bandwidth for amplitude modulation is: (1) 5 kHz (2) 20 kHz (3) 10 kHz (4) 2. 5 kHz

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.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 satellite communication, the uplink frequency band used is: (1) 420 −890 MHz (2) 5. 925 −6. 425 GHz (3) 76 −88 MHz (4) 3. 7 −4. 2 GHz

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

Q31.A solution is prepared by adding 2 g of ′′X′′ to 1 mole of water. Mass percent of ′′X′′in solution is (1) 5% (2) 20% (3) 2% (4) 10% JEE Main 2023 (11 Apr Shift 2) JEE Main Previous Year Paper