Practice Questions

Q25.In the figure given below. a block of mass 𝑀= 490 g placed on a frictionless table is connected with two springs having same spring constant (𝐾= 2 N m-1). If the block is horizontally displaced through 𝑋 m then the number of complete oscillations it will make in 14𝜋 seconds will be ______.

Q25.Two light waves of wavelengths 800 and 600 nm are used in Young's double slit experiment to obtain interference fringes on a screen placed 7 m away from plane of slits. If the two slits are separated by 0. 35 mm , then shortest distance from the central bright maximum to the point where the bright fringes of the two wavelength coincide will be ______ mm.

Q25.Three point charges 𝑞, - 2𝑞 and 2𝑞 are placed on 𝑥 axis at a distance 𝑥= 0, 𝑥= 3 and 𝑥= 𝑅 respectively 4𝑅 from origin as shown. If 𝑞= 2 × 10-6 C and 𝑅= 2 cm, the magnitude of net force experienced by the charge -2𝑞 is _____ N.

Q25.In the given figure the total charge stored in the combination of capacitors is 100 µC. The value of ‘ x’ is ______________.

Q25.A convex lens of refractive index 1. 5 and focal length 18 cm in air is immersed in water. The change in focal length of the lens will be_____ cm. (Given refractive index of water = 43 )

Q25.As shown in the figure, in Young's double slit experiment, a thin plate of thickness t = 10 μm and refractive index μ = 1. 2 is inserted infront of slit S1 . The experiment is conducted in air ( μ = 1 ) and uses a monochromatic light of wavelength λ = 500 nm. Due to the insertion of the plate, central maxima is shifted by a distance of xβ0 . β0 is the fringe-width before the insertion of the plate. The value of the x is ______.

Q25.In the following circuit, the magnitude of current 𝐼1, is ______ A. JEE Main 2023 (30 Jan Shift 1) JEE Main Previous Year Paper - 1 A s-1, then the value of 𝑉AB at this instant will be ______ V.

Q25.Three concentric spherical metallic shells 𝑋, 𝑌 and 𝑍 of radius 𝑎, 𝑏 and 𝑐 respectively 𝑎< 𝑏< 𝑐 have surface charge densities 𝜎, – 𝜎 and 𝜎, respectively. The shells 𝑋 and 𝑍 are at same potential. If the radii of 𝑋 & 𝑌 are 2 cm and 3 cm, respectively. The radius of shell 𝑍 is _____cm. Q26.10 resistors each of resistance 10 Ω can be connected in such as to get maximum and minimum equivalent resistance. The ratio of maximum and minimum equivalent resistance will be________.

Q26.A network of four resistances is connected to 9 V battery, as shown in figure. The magnitude of voltage difference between the points A and B is __________ V.

Q26.A rectangular parallelopiped is measured as 1 cm × 1 cm × 100 cm. If its specific resistance is 3 × 10-7Ω m, then the resistance between its two opposite rectangular faces will be _____ × 10-7Ω.

Q26.As per the given figure, if d𝑡=d𝐼

Q26.As shown in the figure, a plane mirror is fixed at a height of 50 cm from the bottom of tank containing water (μ = 43 ). The height of water in the tank is 8 cm. A small bulb is placed at the bottom of the water tank. The distance of image of the bulb formed by mirror from the bottom of the tank is ______ cm.

Q26.Expression for an electric field is given by →𝐸= 4000 𝑥2 ^i V m-1. The electric flux through the cube of side 20 cm when placed in electric field (as shown in the figure) is ______ V cm. JEE Main 2023 (31 Jan Shift 1) JEE Main Previous Year Paper

Q26.A stream of a positively charged particles having 𝑚= 2 × 1011 C kg-1 and velocity →v0 = 3 × 107 ^𝑖 m s-1 is deflected by an electric field 1 . 8 ^𝑗 kV m-1. The electric field exists in a region of 10 cm along 𝑥 direction. Due to the electric field, the deflection of the charge particles in the 𝑦 direction is _____ mm.

Q26.In the circuit shown, the energy stored in the capacitor is 𝑛 μJ. The value of 𝑛 is _____.

Q26.A parallel plate capacitor with plate area 𝐴 and plate separation 𝑑 is filled with a dielectric material of dielectric constant 𝐾= 4 . The thickness of the dielectric material is 𝑥, where 𝑥< 𝑑. 2𝑑 𝑥= , respectively. If 𝐶1 = 2 μF, the value Let 𝐶1 and 𝐶2 be the capacitance of the system for 𝑥= 13𝑑 and 3 of 𝐶2 is _____ μF .

Q27.An object is placed on the principal axis of convex lens of focal length 10 cm as shown. A plane mirror is placed on the other side of lens at a distance of 20 cm. The image produced by the plane mirror is 5 cm inside the mirror. The distance of the object from the lens is ____ cm.

Q27.A straight wire AB of mass 40 g and length 50 cm is suspended by a pair of flexible leads in uniform magnetic field of magnitude 0 . 40 T as shown in the figure. The magnitude of the current required in the wire to remove the tension in the supporting leads is _____ A. (Take 𝑔= 10 m s-2.

Q27.A straight wire carrying a current of 14 A is bent into a semicircular arc of radius 2 . 2 cm as shown in the figure. The magnetic field produced by the current at the centre 𝑂 of the arc is ____ × 10 – 4 T JEE Main 2023 (10 Apr Shift 2) JEE Main Previous Year Paper

Q27.The ratio of wavelength of spectral lines Hα and Hβ in the Balmer series is 20x . The value of x is _____.

Q27.A hollow cylindrical conductor has length of 3 . 14 m, while its inner and outer diameters are 4 mm and 8 mm respectively. The resistance of the conductor is n × 10-3 𝛺. If the resistivity of the material is 2 . 4 × 10-8 𝛺 m. The value of n is _____.

Q27.An electron in a hydrogen atom revolves around its nucleus with a speed of 6. 76 × 106 m s–1 in an orbit of radius 0. 52 Å. The magnetic field produced at the nucleus of the hydrogen atom is _______ T.

Q27.A beam of light consisting of two wavelengths 7000 A and 5500 A is used to obtain interference pattern in Young's double slit experiment. The distance between the slits is 2. 5 mm and the distance between the plane of slits and the screen is 150 cm. The least distance from the central fringe, where the bright fringes due to both the wavelengths coincide, is n × 10–5 m. The value of n is _____.

Q27.A radioactive element 24292X emits two α-particles, one electron and two positrons. The product nucleus is represented by 234PY . The value of P is ______. JEE Main 2023 (29 Jan Shift 1) JEE Main Previous Year Paper

Q27.In an experiment for estimating the value of focal length of converging mirror, image of an object placed at 40 cm from the pole of the mirror is formed at distance 120 cm from the pole of the mirror. These distances are measured with a modified scale in which there are 20 small divisions in 1 cm. The value of error in 1 measurement of focal length of the mirror is cm. The value of 𝐾 is ______. 𝐾