Practice Questions

Q16.Experimentally it is found that 12. 8 eV energy is required to separate a hydrogen atom into a proton and an electron. So the orbital radius of the electron in a hydrogen atom is 9 × 10−10 m. x The value of the x is: _____. ( 1 eV = 1. 6 × 10−19 J, 1 = 9 × 109 Nm2C2 and electronic charge = 1. 6 × 10−19 C) 4πε0

Q16.Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason R Assertion A : The beam of electrons shows wave nature and exhibit interference and diffraction. Reason R : Davisson Germer Experimentally verified the wave nature of electrons. In the light of the above statements. Choose the most appropriate answer from the options given below : (1) A is correct but R is not correct (2) A is not correct but R is correct (3) Both A and R are correct but R is Not the correct (4) Both A and R are correct and R is the correct explanation of A explanation of A

Q16.A person has been using spectacles of power -1 . 0 diopter for distant vision and a separate reading glass of power 2 . 0 diopters. What is the least distance of distinct vision for this person: (1) 10 cm (2) 40 cm (3) 30 cm (4) 50 cm

Q16.Two parallel plate capacitors C1 and C2 each having capacitance of 10 μF are individually charged by a 100 V D.C. source. Capacitor C1 is kept connected to the source and a dielectric slab is inserted between it plates. Capacitor C2 is disconnected from the source and then a dielectric slab is inserted in it. Afterwards the capacitor C1 is also disconnected from the source and the two capacitors are finally connected in parallel combination. The common potential of the combination will be _____ V . (Assuming Dielectric constant = 10 )

Q16.The variation of stopping potential V0 as a function of the frequency ( 𝜈) of the incident light for a metal is shown in figure. The work function of the surface is JEE Main 2023 (10 Apr Shift 2) JEE Main Previous Year Paper (1) 2 . 98 eV (2) 2 . 07 eV (3) 1 . 36 eV (4) 18 . 6 eV

Q16.Given below are two statements : Statement I : If the Brewster's angle for the light propagating from air to glass is 𝜃𝐵, then Brewster's angle for the light propagating from glass to air is 𝜋 - 𝜃𝐵. 2 Statement II : The Brewster's angle for the light propagating from glass to air is tan-1𝜇g, where 𝜇g is the refractive index of glass. In the light of the above statements, choose the correct answer from the options given below : (1) Both Statements I and Statement II are true. (2) Statement I is true but Statement II is false. (3) Both Statement I and Statement II are false. (4) Statement I is false but Statement II is true.

Q16.An object is placed at a distance of 12 cm in front of a plane mirror. The virtual and erect image is formed by the mirror. Now the mirror is moved by 4 cm towards the stationary object. The distance by which the position of image would be shifted, will be (1) 4 cm towards mirror (2) 8 cm towards mirror (3) 8 cm away from mirror (4) 2 cm towards mirror

Q16.A point charge q1 = 4q0 is placed at origin. Another point charge q2 = −q0 is placed at x = 12 cm. Charge of proton is q0 . The proton is placed on x-axis so that the electrostatic force on the proton in zero. In this situation, the position of the proton from the origin is ______ cm.

Q16.A capacitor of capacitance C is charged to a potential V . The flux of the electric field through a closed surface enclosing the positive plate of the capacitor is: (1) CV (2) Zero ε0 (3) 2 CV (4) CV ε0 2ε0

Q16.For a charged spherical ball, electrostatic potential inside the ball varies with r as V = 2ar2 + b. Here, a and b are constant and r is the distance from the center. The volume charge density inside the ball is −λaε. The value of λ is ______. ε = permittivity of medium.

Q16.Given below are two statements : One is labelled as Assertion A and the other is labelled as Reason R. Assertion A : Two metallic spheres are charged to the same potential. One of them is hollow and another is solid, and both have the same radii. Solid sphere will have lower charge than the hollow one. Reason R : Capacitance of metallic spheres depend on the radii of spheres. In the light of the above statements, choose the correct answer from the options given below. (1) A is false but R is true (2) Both A and R are true and R is the correct explanation of A (3) A is true but R is false (4) Both A and R are true but R is not the correct explanation of A

Q17.A proton moving with one tenth of velocity of light has a certain de Broglie wavelength of 𝜆. An alpha particle having certain kinetic energy has the same de-Brogle wavelength 𝜆. The ratio of kinetic energy of proton and that of alpha particle is : (1) 2 : 1 (2) 4 : 1 (3) 1 : 2 (4) 1 : 4 JEE Main 2023 (01 Feb Shift 1) JEE Main Previous Year Paper

Q17.The equivalent resistance between A and B is _______. JEE Main 2023 (30 Jan Shift 2) JEE Main Previous Year Paper . (1) 2 Ω (2) 1 Ω 3 2 (3) 3 Ω (4) 1 Ω 2 3

Q17.A uniform metallic wire carries a current 2 A, when 3. 4 V battery is connected across it. The mass of uniform metallic wire is 8. 92 × 10−3 kg, density is 8. 92 × 103 kg m−3 and resistivity is 1. 7 × 10−8 Ω −m The length of wire is : (1) l = 6. 8 m (2) l = 10 m (3) l = 5 m (4) l = 100 m

Q17.A cell of emf 90 V is connected across series combination of two resistors each of 100 Ω resistance. A voltmeter of resistance 400 Ω is used to measure the potential difference across each resistor. The reading of the voltmeter will be: (1) 40 V (2) 45 V (3) 80 V (4) 90 V

Q17.Given below are two statements : One is labelled as Assertion A and the other is labelled as Reason R. Assertion A : For measuring the potential difference across a resistance of 600 Ω, the voltmeter with resistance 1000 Ω will be preferred over voltmeter with resistance 4000 Ω . Reason R : Voltmeter with higher resistance will draw smaller current than voltmeter with lower resistance. In the light of the above statements, choose the most appropriate answer from the options given below (1) A is not correct but R is correct (2) Both A and R are correct and R is the correct explanation of A (3) Both A and R are correct but R is not the correct (4) A is correct but R is not correct explanation of A JEE Main 2023 (01 Feb Shift 2) JEE Main Previous Year Paper

Q17.With the help of potentiometer, we can determine the value of emf of a given cell. The sensitivity of the potentiometer is (A) directly proportional to the length of the potentiometer wire (B) directly proportional to the potential gradient of the wire (C) inversely proportional to the potential gradient of the wire (D) inversely proportional to the length of the potentiometer wire Choose the correct option for the above statements: (1) B and D only (2) A and C only (3) A only (4) C only

Q17.As shown in the figure, two parallel plate capacitors having equal plate area of 200 cm2 are joined in such a way that a ≠b. The equivalent capacitance of the combination is xε0F . The value of x is _____.

Q17.In the given circuit. C1 = 2μF, C2 = 0. 2μF, C3 = 2μF, C4 = 4μF, C5 = 2μF, C6 = 2μF. The charge stored on capacitor C4 is ______ μC. JEE Main 2023 (11 Apr Shift 2) JEE Main Previous Year Paper

Q17.Different combination of 3 resistors of equal resistance R are shown in the figures. The increasing order for power dissipation is: (A) (B) JEE Main 2023 (13 Apr Shift 1) JEE Main Previous Year Paper (C) (D) (1) PB < PC < PD < PA (2) PC < PD < PA < PB (3) PC < PB < PA < PD (4) PA < PB < PC < PD

Q17.From the photoelectric effect experiment, following observations are made. Identify which of these are correct A. The stopping potential depends only on the work function of the metal. B. The saturation current increases as the intensity of incident light increases. C. The maximum kinetic energy of a photo electron depends on the intensity of the incident light. D. Photoelectric effect can be explained using wave theory of light. Choose the correct answer from the options given below: (1) B, C only (2) A, C, D only (3) B only (4) A, B, D only

Q17.An electric dipole of dipole moment is 6. 0 × 10−6 C m placed in a uniform electric field of 1. 5 × 103 N C−1 in such a way that dipole moment is along electric field. The work done in rotating dipole by 180° in this field will be_______ mJ.

Q17.The half life of a radioactive substance is 𝑇. The time taken, for disintegrating 7 𝑡ℎ part of its original mass will 8 be: (1) 2𝑇 (2) 3𝑇 (3) 𝑇 (4) 8𝑇

Q17.In a Young’s double slit experiment, the ratio of amplitude of light coming from slits is 2 : 1. The ratio of the maximum to minimum intensity in the interference pattern is (1) 9 : 4 (2) 25 : 9 (3) 2 : 1 (4) 9 : 1

Q17.If a source of electromagnetic radiation having power 15 kW produces 1016 photons per second, the radiation belongs to a part of spectrum is : (Take Planck constant ℎ = 6 × 10-34 J s) (1) Micro waves (2) Ultraviolet rays (3) Gamma rays (4) Radio waves