Practice Questions

Q15.Two polaroids 𝐴 and 𝐵 are placed in such a way that the pass-axis of polaroids are perpendicular to each other. Now, another polaroid 𝐶 is placed between 𝐴 and 𝐵 bisecting angle between them. If intensity of unpolarised light is 𝐼0 then intensity of transmitted light after passing through polaroid 𝐵 will be : (1) 𝐼0 (2) 𝐼0 4 2 𝐼0 (3) (4) Zero 8

Q15.If →𝐸 and →𝐾 represent electric field and propagation vectors of the EM waves in vacuum, then magnetic field vector is given by: (𝜔- angular frequency) 1 → → → → (1) 𝐾× 𝐸 (2) 𝜔𝐸× 𝐾 𝜔 (3) 𝜔→𝐾× →𝐸 (4) →𝐾× →𝐸

Q15.For a certain organ pipe, the first three resonance frequencies are in the ratio of 1 : 3 : 5 respectively. If the frequency of fifth harmonic is 405 Hz and the speed of sound in air is 324 m s–1 the length of the organ pipe is _____ m .

Q15.In a series 𝐿𝑅 circuit with 𝑋𝐿= 𝑅, power factor is 𝑃1. If a capacitor of capacitance 𝐶 with 𝑋𝐶= 𝑋𝐿 is added to the circuit the power factor becomes 𝑃2. The ratio of 𝑃1 to 𝑃2 will be : (1) 1: 3 (2) 1: √2 (3) 1: 1 (4) 1: 2

Q15.The ratio of intensities at two points P and Q on the screen in a Young's double slit experiment where phase difference between two waves of same amplitude are π and π respectively are 3 2, (1) 2 : 3 (2) 1 : 3 (3) 3 : 1 (4) 3 : 2

Q15.Two charges of each magnitude 0. 01 C and separated by a distance of 0. 4 mm constitute an electric dipole. If → → the dipole is placed in an uniform electric field E of 10 dyne ⋅C−1 making 30∘ angle with E, the magnitude of torque acting on dipole is: (1) 4. 0 × 10−10 N m (2) 1. 0 × 10−8 N m (3) 1. 5 × 10−9 N m (4) 2. 0 × 10−10 N m

Q15. As per the given graph, choose the correct representation for curve 𝐴 and curve 𝐵 {Where 𝑋𝐶= Reactance of pure capacitive circuit connected with A.C. source 𝑋𝐿= Reactance of pure inductive circuit connected with A.C. source 𝑅= Impedance of pure resistive circuit connected with A.C. source 𝑍= Impedance of the 𝐿𝐶𝑅 series circuit } (1) 𝐴= 𝑋𝐶, 𝐵= 𝑅 (2) 𝐴= 𝑋𝐿, 𝐵= 𝑅 (3) 𝐴= 𝑋𝐿, 𝐵= 𝑍 (4) 𝐴= 𝑋𝐶, 𝐵= 𝑋𝐿

Q15.A uniform electric field of 10 N C−1 is created between two parallel charged plates (as shown in figure). An electron enters the field symmetrically between the plates with a kinetic energy 0. 5 eV. The length of each plate is 10 cm. The angle (θ) of deviation of the path of electron as it comes out of the field is ______(in degree). JEE Main 2023 (25 Jan Shift 1) JEE Main Previous Year Paper

Q15.A cubical volume is bounded by the surfaces x = 0, x = a, y = 0, y = a, z = 0, z = a . The electric field in → the region is given by E = E0xˆi. Where E0 = 4 × 104 NC−1 m−1 . If a = 2 cm , the charge contained in the cubical volume is Q × 10–14 C . The value of Q is ______. (Take ϵ0 = 9 × 10−12 C2 N−1m−2 )

Q15.The electric potential at the centre of two concentric half rings of radii R1 and R2 , having same linear charge density λ is . (1) 2λ (2) λ ∈0 2∈0 (3) λ (4) λ 4∈0 ∈0

Q15.A monochromatic light wave with wavelength 𝜆1 and frequency 𝜈1 in air enters another medium. If the angle of incidence and angle of refraction at the interface are 45° and 30° respectively, then the wavelength 𝜆2 and frequency 𝜈2 of the refracted wave are: (1) 𝜆2 = √2𝜆1, 𝜈2 = 𝜈1 (2) 𝜆2 = 𝜆1, 𝜈2 = 1 √2𝜈1 (3) 𝜆2 = 𝜆1, 𝜈2 = √2𝜈1 (4) 𝜆2 = 1 𝜈2 = 𝜈1 √2𝜆1,

Q15.If V is the gravitational potential due to sphere of uniform density on its surface, then its value at the centre of sphere will be: (1) 4 V (2) V 3 2 (3) V (4) 3V 2

Q15.As shown in the figure, a point charge Q is placed at the centre of conducting spherical shell of inner radius a and outer radius b. The electric field due to charge Q in three different regions I, II and III is given by : (I : r < a, II : a < r < b, III : r > b) (1) EI = 0, EII = 0, EIII ≠0 (2) EI ≠0, EII = 0, EIII ≠0 (3) EI ≠0, EII = 0, EIII = 0 (4) EI = 0, EII = 0, EIII = 0

Q15.Given below are two statements: Statement I: Maximum power is dissipated in a circuit containing an inductor, a capacitor and a resistor connected in series with an 𝐴𝐶 source, when resonance occurs. Statement II: Maximum power is dissipated in a circuit containing pure resistor due to zero phase difference between current and voltage. In the light of the above statements, choose the correct answer from the options given below: (1) Statement I is false but Statement II is true (2) Both Statement I and Statement II are true (3) Statement I is true but Statement II is false (4) Both Statement I and Statement II are false

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.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.Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R. Assertion A : If an electric dipole of dipole moment 30 × 10–5 C m is enclosed by a closed surface, the net flux coming out of the surface will be zero. Reason R : Electric dipole consists of two equal and opposite charges. In the light of above, statements, choose the correct answer from the options given below. JEE Main 2023 (12 Apr Shift 1) JEE Main Previous Year Paper (1) Both A and R are true and R is the correct (2) A is false but R is true explanation of A (3) A is true but R is false (4) Both A and R are true and R is NOT the correct explanation of A

Q16.A 600 pF capacitor is charged by 200 V supply. It is then disconnected from the supply and is connected to another uncharged 600 pF capacitor. Electrostatic energy lost in the process is _____ μJ.

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.The critical angle for a denser-rarer interface is 45°. The speed of light in rarer medium is 3 × 108 m s-1. The speed of light in the denser medium is: (1) 3 . 12 × 107 m s-1 (2) 5 × 107 m s-1 (3) 2 . 12 × 108 m s-1 (4) √2 × 108 m s-1

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.A parallel plate capacitor has plate area 40 cm2 and plates separation 2 mm . The space between the plates is filled with a dielectric medium of a thickness 1 mm and dielectric constant 5 . The capacitance of the system is: (1) 24ε0 F (2) 103 ε0 F (3) 10 3 ε0 F (4) 10ε0 F

Q16.A train blowing a whistle of frequency 320 Hz approaches an observer standing on the platform at a speed of 66 m s−1 . The frequency observed by the observer will be (given speed of sound = 330 m s−1 ) ______ Hz.

Q16.Graphical variation of electric field due to a uniformly charged insulating solid sphere of radius R, with distance r from the centre O is represented by: JEE Main 2023 (08 Apr Shift 1) JEE Main Previous Year Paper (1) Dig (2) (3) (4)

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