Practice Questions

Q18.The energy released in the fusion of 2 kg of hydrogen deep in the sun is EH and the energy released in the fission of 2 kg of 235U is EU . The ratio EHEU is approximately: (Consider the fusion reaction as 4 ∣H + 2e−→42He + 2v + 6γ + 26.7MeV, energy released in the fission reaction of 235U is 200MeV per fission nucleus and NA = 6.023 × 1023) JEE Main 2024 (09 Apr Shift 2) JEE Main Previous Year Paper (1) 7.62 (2) 25.6 (3) 15.04 (4) 9.13

Q18.The angular momentum of an electron in a hydrogen atom is proportional to : (Where r is the radius of orbit of electron) (1) r (2) √r (3) 1 (4) 1 √r r

Q18.Two sources of light emit with a power of 200 W. The ratio of number of photons of visible light emitted by each source having wavelengths 300 nm and 500 nm respectively, will be : (1) 1 : 5 (2) 1 : 3 (3) 5 : 3 (4) 3 : 5

Q18.The work function of a substance is 3. 0 eV. The longest wavelength of light that can cause the emission of photoelectrons from this substance is approximately: (1) 215 nm (2) 414 nm (3) 400 nm (4) 200 nm

Q18.In a nuclear fission reaction of an isotope of mass 𝑀, three similar daughter nuclei of same mass are formed. The speed of a daughter nuclei in terms of mass defect 𝛥𝑀 will be : JEE Main 2024 (30 Jan Shift 2) JEE Main Previous Year Paper (1) 2𝑐𝛥𝑀 (2) 𝛥𝑀𝑐2 √ 𝑀 3 (3) 2𝛥𝑀 (4) 3𝛥𝑀 𝑐√ 𝑀 𝑐√ 𝑀

Q18.The de-Broglie wavelength of an electron is the same as that of a photon. If velocity of electron is 25% of the velocity of light, then the ratio of K.E. of electron and K.E. of photon will be: (1) 1 (2) 1 1 8 (3) 8 (4) 1 1 4

Q18.The ratio of the shortest wavelength of Balmer series to the shortest wavelength of Lyman series for hydrogen atom is : (1) 4 : 1 (2) 1 : 4 (3) 2 : 1 (4) 1 : 2 JEE Main 2024 (06 Apr Shift 1) JEE Main Previous Year Paper

Q18.The minimum energy required by a hydrogen atom in ground state to emit radiation in Balmer series is nearly : (1) 1 . 5 eV (2) 13 . 6 eV (3) 1 . 9 eV (4) 12 . 1 eV

Q18.In a hypothetical fission reaction 92X 236 →56Y 141 + 36Z 92 + 3R The identity of emitted particles ( R) is : (1) Electron (2) Neutron (3) γ -radiations (4) Proton 1

Q18.According to Bohr's theory, the moment of momentum of an electron revolving in 4th orbit of hydrogen atom is: (1) h (2) h π 2π (3) 8 hπ (4) 2 hπ JEE Main 2024 (04 Apr Shift 2) JEE Main Previous Year Paper

Q19.In the given circuit, the voltage across load resistance ( 𝑅𝐿) is: (1) 8 . 75 V (2) 9 . 00 V (3) 8 . 50 V (4) 14 . 00 V

Q19.The ratio of the magnitude of the kinetic energy to the potential energy of an electron in the 5th excited state of a hydrogen atom is : (1) 4 (2) 14 (3) 1 (4) 1 2

Q19.If the wavelength of the first member of Lyman series of hydrogen is 𝜆. The wavelength of the second member will be 27 32 (1) 32𝜆 (2) 27𝜆 (3) 27 𝜆 (4) 5 5 27𝜆

Q19.The correct truth table for the following logic circuit is : (1) A B Y (2) A B Y 0 0 1 0 0 0 0 1 1 0 1 1 1 0 0 1 0 0 1 1 1 1 1 1 (3) A B Y (4) A B Y 0 0 1 0 0 0 0 1 1 0 1 0 1 0 0 1 0 0 1 1 0 1 1 1

Q19.The output (Y ) of logic circuit given below is 0 only when : (1) A = 1, B = 0 (2) A = 0, B = 1 (3) A = 0, B = 0 (4) A = 1, B = 1

Q19.The truth table of the given circuit diagram is : JEE Main 2024 (27 Jan Shift 2) JEE Main Previous Year Paper (1) A B Y (2) A B Y 0 0 1 0 0 0 0 1 0 0 1 1 1 0 0 1 0 1 1 1 1 1 1 0 (3) A B Y (4) A B Y 0 0 0 0 0 1 0 1 0 0 1 1 1 0 0 1 0 1 1 1 1 1 1 0

Q19.The acceptor level of a p-type semiconductor is 6eV. The maximum wavelength of light which can create a hole would be : Given hc = 1242eVnm. (1) 414 nm (2) 103.5 nm (3) 207 nm (4) 407 nm

Q19.From the statements given below : (A) The angular momentum of an electron in 𝑛𝑡ℎ orbit is an integral multiple of ℎ. (B) Nuclear forces do not obey inverse square law. JEE Main 2024 (01 Feb Shift 2) JEE Main Previous Year Paper (C) Nuclear forces are spin dependent. (D) Nuclear forces are central and charge independent. (E) Stability of nucleus is inversely proportional to the value of packing fraction. Choose the correct answer from the options given below : (1) (A), (B), (C), (D) only (2) (A), (C), (D), (E) only (3) (A), (B), (C), (E) only (4) (B), (C), (D), (E) only

Q19.Least count of a vernier caliper is 20 N cm . The value of one division on the main scale is 1 mm . Then the number of divisions of main scale that coincide with N divisions of vernier scale is : (1) (2 N −1) (2) ( 2 2N−1N ) (3) ( 2 N−12 ) (4) ( 220N−1N )

Q19.The output Y of following circuit for given inputs is : (1) Λ ⋅B(Λ + B) (2) 0 – (3) A ⋅B (4) A ⋅B

Q19.A light emitting diode (LED) is fabricated using GaAs semiconducting material whose band gap is 1.42eV. The wavelength of light emitted from the LED is : (1) 1400 nm (2) 650 nm (3) 875 nm (4) 1243 nm

Q19. Identify the logic gate given in the circuit: (1) NAND-gate (2) AND gate (3) NOR gate (4) OR- gate

Q19.An electron rotates in a circle around a nucleus having positive charge Ze. Correct relation between total energy (E) of electron to its potential energy (U) is : (1) E = U (2) 2E = U (3) 2E = 3U (4) E = 2U

Q19.The output of the given circuit diagram is JEE Main 2024 (31 Jan Shift 2) JEE Main Previous Year Paper (1) (2) (3) (4)

Q19.The explosive in a Hydrogen bomb is a mixture of 1H2, 1H3 and 3Li6 in some condensed form. The chain reaction is given by 3Li6 + 0n1 →2He4 + 1H3; 1H2 + 1H3 →2He4 + 0n1 During the explosion the energy released is approximately [Given : M(Li) = 6. 01690 amu, M(1H2) = 2. 01471 amu, M(2He4) = 4. 00388 amu and 1 amu = 931. 5 MeV] (1) 28. 12 MeV (2) 12. 64 MeV (3) 16. 48 MeV (4) 22. 22 MeV