Practice Questions

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.A point charge 2 × 10–2 C is moved from P to S in a uniform electric field of 30 N C–1 directed along positive x-axis. If coordinates of P and S are (1, 2, 0) m and (0, 0, 0) m respectively, the work done by electric field will be (1) 1200 mJ (2) 600 mJ (3) −600 mJ (4) −1200 mJ

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.Electric potential at a point P due to a point charge of 5 × 10−9 C is 50 V . The distance of P from the point charge is: (Assume, 1 = 9 × 109 N m2 C−2 ) 4πε0 (1) 9 cm (2) 3 cm (3) 0. 9 cm (4) 90 cm

Q15.In a cuboid of dimension 2L × 2L × L , a charge q is placed at the centre of the surface S having area of 4L2 . The flux through the opposite surface to S is given by (1) q (2) q 12∈0 3∈0 (3) q (4) q 2∈0 6∈0

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. 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.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.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.A dipole comprises of two charged particles of identical magnitude q and opposite in nature. The mass m of the positive charged particle is half of the mass of the negative charged particle. The two charges are separated → by a distance l . If the dipole is placed in a uniform electric field E ; in such a way that dipole axis makes a JEE Main 2023 (06 Apr Shift 2) JEE Main Previous Year Paper → very small angle with the electric field, E . The angular frequency of the oscillations of the dipole when released is given by: (1) √3qE2ml (2) √8qEml (3) √4qEml (4) √8qE3ml

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.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.Match List I with List II List I List II A Troposphere I Approximate 65 −75 km over Earth’s surface B E-Part of Stratosphere II Approximate 300 km over Earth’s surface C F2 -Part of Thermosphere III Approximate 10 km over Earth’s surface D D-Part of Stratosphere IV Approximate 100 km over Earth’s surface Choose the correct answer from the options given below : (1) A-III, B-IV, C-II, D-I (2) A-I, B-II, C-IV, D-III (3) A-I, B-IV, C-III, D-II (4) A-III, B-II, C-I, D-IV

Q15.A 12 V battery connected to a coil of resistance 6 Ω through a switch, drives a constant current in the circuit. The switch is opened in 1 ms. The emf induced across the coil is 20 V. The inductance of the coil is : (1) 10 mH (2) 8 mH (3) 5 mH (4) 12 mH

Q15.Match the List-I with List-II: List I List II A Microwaves I Radioactive decay of the nucleus B Gamma rays II Rapid acceleration and deceleration of electron in aerials C Radio waves III Inner shell electrons D X-rays IV Klystron valve Choose the correct answer from the options given below: (1) A-I, B-II, C-III, D-IV (2) A-IV, B-I, C-II, D-III (3) A-I, B-III, C-IV, D-II (4) A-IV, B-III, C-II, D-I Q16.‘𝑛’ polarizing sheets are arranged such that each makes an angle 45° with the proceeding sheet. An 𝐼 unpolarized light of intensity 𝐼 is incident into this arrangement. The output intensity is found to be . The 64 value of 𝑛 will be: (1) 3 (2) 6 (3) 5 (4) 4

Q16.The kinetic energy of an electron, 𝛼- particle and a proton are given as 4𝐾, 2𝐾 and 𝐾 respectively. The de- Broglie wavelength associated with electron ( 𝜆𝑒) , 𝛼- particle ( 𝜆𝛼) and the proton (𝜆𝑝) are as follows: (1) 𝜆𝛼= 𝜆𝑝> 𝜆𝑒 (2) 𝜆𝛼< 𝜆𝑝< 𝜆𝑒 (3) 𝜆𝛼= 𝜆𝑝< 𝜆𝑒 (4) 𝜆𝛼> 𝜆𝑝> 𝜆𝑒

Q16.In an electromagnetic wave, at an instant and at a particular position, the electric field is along the negative z- axis and magnetic field is along the positive x-axis. Then the direction of propagation of electromagnetic wave is: (1) positive z-axis (2) positive y-axis (3) at 45°angle from positive y -axis (4) negative y-axis

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.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 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.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 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.Match List-I with List II of Electromagnetic waves with corresponding wavelength range: List I List II (A) Microwave (I) 400 nm to 1 nm (B) Ultraviolet (II) 1 nm to 10–3 nm (C) X -Ray (III) 1 mm to 700 nm (D) Infra-red (IV) 0. 1 m to 1 mm Choose the correct answer from the options given below: (1) (A) −(IV), (B) −(I), (C) −(II), (D) −(III) (2) (A) −(IV), (B) −(I), (C) −(III), (D) −(II) (3) (A) −(IV), (B) −(II), (C) −(I), (D) −(III) (4) (A) −(I), (B) −(IV), (C) −(II), (D) −(III)

Q16.A parallel plate capacitor with air between the plate has a capacitance of 15 pF . The separation between the plate becomes twice and the space between them is filled with a medium of dielectric constant 3. 5 . Then the capacitance becomes x 4 pF . The value of x is____. JEE Main 2023 (24 Jan Shift 2) JEE Main Previous Year Paper

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.