Practice Questions

Q22.If the earth suddenly shrinks to 1 of its original volume with its mass remaining the same, the period of 64th 24 rotation of earth becomes 𝑥ℎ. The value of 𝑥 is ________

Q22.A series LCR circuit consists of R = 80 Ω. XL = 100 Ω , and XC = 40 Ω. The input voltage is 2500 cos(100πt) V. The amplitude of current, in the circuit, is _____ A .

Q22.A square shaped coil of area 70 cm2 having 600 turns rotates in a magnetic field of 0. 4 Wb m–2 , about an axis which is parallel to one of the side of the coil and perpendicular to the direction of field. If the coil JEE Main 2023 (01 Feb Shift 2) JEE Main Previous Year Paper completes 500 revolution in a minute, the instantaneous emf when the plane of the coil is inclined at 60° with the field, will be ______ V. (Take π = 227 )

Q22.A force of -𝑃 ^𝑘 acts on the origin of the coordinate system. The torque about the point ( 2, - 3 ) is 𝑃(𝑎 ^𝑖+ 𝑏 ^𝑗) 𝑎 𝑥 , The ratio of is The value of 𝑥 is 𝑏 2.

Q22.An inductor of inductance 2 μH is connected in series with a resistance, a variable capacitor and an AC source of frequency 7 kHz. The value of capacitance for which maximum current is drawn into the circuit is x1 F , where the value of x is ______. (Take π = 227 )

Q23.A thin prism P1 with an angle 6° and made of glass of refractive index 1. 54 is combined with another prism P2 made from glass of refractive index 1. 72 to produce dispersion without average deviation. The angle of prism P2 is : (1) 6° (2) 1. 3° (3) 7. 8° (4) 4. 5°

Q23.A vessel of depth d is half filled with oil of refractive index n1 and the other half is filled with water of refractive index n2. The apparent depth of this vessel when viewed from above will be- (1) 2d(n1+n2) (2) d(n1+n2) n1+n2 2n1n2 (3) dn1n2 (4) dn1n2 2(n1+n2) (n1+n2)

Q23.Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R Assertion A : EM waves used for optical communication have longer wavelengths than that of microwave, employed in Radar technology. Reason R : Infrared EM waves are more energetic than microwaves, (used in Radar) In the light of given 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 but R is NOT 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 the correct explanation of A

Q23.In a Young’s double slit experiment, two slits are illuminated with a light of wavelength 800 nm . The line joining A1P is perpendicular to A1A2 as shown in the figure. If the first minimum is detected at P , the value of slits separation a will be : JEE Main 2023 (29 Jan Shift 1) JEE Main Previous Year Paper The distance of screen from slits D = 5 cm . (1) 0. 4 mm (2) 0. 5 mm (3) 0. 2 mm (4) 0. 1 mm

Q23.A certain pressure '𝑃' is applied to 1 litre of water and 2 litre of a liquid separately. Water gets compressed to 0 . 01% whereas the liquid gets compressed to 0 . 03%. The ratio of Bulk modulus of water to that of the liquid 3 is 𝑥. The value of 𝑥 is ______.

Q23.All electromagnetic wave is transporting energy in the negative z direction. At a certain point and certain time the direction of electric field of the wave is along positive y direction. What will be the direction of the magnetic field of the wave at that point and instant? JEE Main 2023 (25 Jan Shift 1) JEE Main Previous Year Paper (1) Positive direction of x (2) Positive direction of z (3) Negative direction of x (4) Negative direction of y

Q23.Solid sphere 𝐴 is rotating about an axis 𝑃𝑄. If the radius of the sphere is 5 cm, then its radius of gyration about 𝑃𝑄 will be √𝑥 cm. The value of 𝑥 is _____.

Q23.The electric field and magnetic field components of an electromagnetic wave going through vacuum is described by Ex = E0 sin(kz −ωt) By = B0 sin(kz −ωt) Then the correct relation between E0 and B0 is given by (1) E0B0 = ωk (2) E0 = kB0 (3) kE0 = ωB0 (4) ωE0 = kB0

Q23.A capacitor of capacitance 150. 0 μF is connected to an alternating source of emf given by E = 36 sin(120πt) V. The maximum value of current in the circuit is approximately equal to: (1) 2 A (2) √2 A (3) 2√2 A (4) 1 A √2 → →

Q23.A wire of length 1 m moving with velocity 8 m s−1 at right angles to a magnetic field of 2 T. The magnitude of induced emf, between the ends of wire will be ___________. (1) 20 V (2) 8 V (3) 12 V (4) 16 V

Q23.The waves emitted when a metal target is bombarded with high energy electrons are (1) Microwaves (2) Infrared rays (3) X-rays (4) Radio Waves

Q23.An oscillating LC circuit consists of a 75 mH inductor and a 1. 2 µF capacitor. If the maximum charge to the capacitor is 2. 7 µC. The maximum current in the circuit will be _______ mA.

Q23.A solid sphere of mass 1 kg rolls without slipping on a plane surface. Its kinetic energy is 7 × 10-3 J. The speed of the centre of mass of the sphere is ______ cm s-1.

Q23.The general displacement of a simple harmonic oscillator is 𝑥= 𝐴 sin 𝜔𝑡. Let 𝑇 be its time period. The 𝑇 slope of its potential energy (𝑈) – time (𝑡) curve will be maximum when 𝑡= 𝛽. The value of 𝛽 is ______.

Q23.Figure below shows a liquid being pushed out of the tube by a piston having area of cross section 2 . 0 cm2. The area of cross section at the outlet is 10 mm2. If the piston is pushed at a speed of 4 cm s-1, the speed of outgoing fluid is _____ cm s-1

Q23.There is an air bubble of radius 1. 0 mm in a liquid of surface tension 0. 075 N m–1 and density 1000 kg m–3 at a depth of 10 cm below the free surface. The amount by which the pressure inside the bubble is greater than the atmospheric pressure is _______ Pa(g = 10 m s−2).

Q23.Two plates A and B have thermal conductivities 84 W m-1 K-1 and 126 W m-1 K-1 respectively. They have same surface area and same thickness. They are placed in contact along their surfaces. If the temperatures of the outer surfaces of A and B are kept at 100∘C and 0∘C respectively, then the temperature of the surface of contact in steady state is_____ ∘C.

Q23.Match List I and List II List I List II A Microwaves I Physiotherapy B UV rays II Treatment of cancer JEE Main 2023 (31 Jan Shift 2) JEE Main Previous Year Paper C Infra-red rays III Lasik eye surgery D X-rays IV Aircraft navigation Choose the correct answer from the option given below: (1) A-II, B-IV, C-III, D-I (2) A-IV, B-I, C-II, D-III (3) A-IV, B-III, C-I, D-II (4) A-III, B-II, C-I, D-IV

Q23.A solid sphere of mass 500 g radius 5 cm is rotated about one of its diameter with angular speed of 10 rad s-1. If the moment of inertia of the sphere about its tangent is 𝑥× 10-2 times its angular momentum about the diameter. Then the value of 𝑥 will be

Q23.Two wires each of radius 0 . 2 cm and negligible mass, one made of steel and the other made of brass are loaded as shown in the figure. The elongation of the steel wire is ______10 – 6 m. [Young's modulus for steel = 2 × 1011 N m – 2 and 𝑔= 10 m s – 2] JEE Main 2023 (10 Apr Shift 1) JEE Main Previous Year Paper