Practice Questions

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.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.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.An organ pipe 40 cm long is open at both ends. The speed of sound in air is 360 m s−1 . The frequency of the second harmonic is _ ________ Hz.

Q15.Considering a group of positive charges, which of the following statements is correct? (1) Net potential of the system cannot be zero at a (2) Net potential of the system at a point can be zero point but net electric field can be zero at that but net electric field can't be zero at that point point (3) Both the net potential and the net field can be (4) Both the net potential and the net electric field zero at a point cannot be zero at a point

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.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

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.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.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.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.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.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

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.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.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,

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.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 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 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.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.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.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.A thin infinite sheet charge and an infinite line charge of respective charge densities +σ and +λ are placed parallel at 5 m distance from each other. Points P and Q are at π3 m and π4 m perpendicular distances from line charge towards sheet charge, respectively. Ep and Eq are the magnitudes of resultant electric field intensities at point P and Q respectively. If EP = a4 for 2|σ| = |λ|, then the value of a is _____. EQ

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