Practice Questions

Q27.The equivalent capacitance between points 𝐴 and 𝐵 in below shown figure will be _____ 𝜇F.

Q27.In the given figure, the value of 𝑉0 will be _____ V.

Q27.The current density in a cylindrical wire of radius 4 mm is 4 × 106 A m−2 . The current through the outer portion of the wire between radial distances R and R is _____ π A. 2

Q27.The effective current I in the given circuit at very high frequencies will be _____ A . JEE Main 2022 (26 Jul Shift 1) JEE Main Previous Year Paper

Q27.A 110 V, 50 Hz, AC source is connected in the circuit (as shown in figure). The current through the resistance 55 Ω, at resonance in the circuit, will be _____ A.

Q27.Two identical thin biconvex lenses of focal length 15 cm and refractive index 1. 5 are in contact with each other. The space between the lenses is filled with a liquid of refractive index 1. 25 . The focal length of the JEE Main 2022 (24 Jun Shift 1) JEE Main Previous Year Paper combination is _____ cm.

Q27.A closely wounded circular coil of radius 5 cm produces a magnetic field of 37. 68 × 10−4 T at its center. The current through the coil is _____ A . [Given, number of turns in the coil is 100 and π = 3. 14]

Q27.Current measured by the ammeter (A) in the reported circuit when no current flows through 10Ω resistance, will be _____ A . JEE Main 2022 (28 Jun Shift 1) JEE Main Previous Year Paper

Q28.A metallic rod of length 20 cm is placed in North-South direction and is moved at a constant speed of 20 m s−1 towards East. The horizontal component of the Earth's magnetic field at that place is 4 × 10−3 T and the angle of dip is 45°. The emf induced in the rod is _____ mV . JEE Main 2022 (27 Jun Shift 2) JEE Main Previous Year Paper

Q28.A parallel beam of light is allowed to fall on a transparent spherical globe of diameter 30 cm and refractive index 1. 5 . The distance from the centre of the globe at which beam of light can converge is _____ mm. Q29. √d1 and √d2 are the impact parameters corresponding to scattering angles 60° and 90° respectively, when an α particle is approaching a gold nucleus. For d1 = xd2 , the value of x will be _____ .

Q28.A sample contains 10−2 kg each of two substances A and B with half lives 4 s and 8 s respectively. The ratio of their atomic weights is 1 : 2 . The ratio of the amounts of A and B after 16 s is 100x . The value of x is _____ .

Q28.The half life of a radioactive substance is 5 years. After x years a given sample of the radioactive substance gets reduced to 6. 25% of its initial value. The value of x is ____

Q28.For the given circuit the current through battery of 6 V just after closing the switch ' S ' will be _____ A . ​

Q28.To light, a 50 W, 100 V lamp is connected, in series with a capacitor of capacitance 50 μF, with π√x 200 V, 50 Hz AC source. The value of x will be _____ .

Q28.The frequencies at which the current amplitude in an LCR series circuit becomes times its maximum value, √2 are 212 rad s-1 and 232 rad s-1. The value of resistance in the circuit is 𝑅= 5 Ω. The self inductance in the circuit is _____ mH.

Q28.A small bulb is placed at the bottom of a tank containing water to a depth of √7 m. The refractive index of water is 4 . The area of the surface of water through which light from the bulb can emerge out is xπ m2 . The 3 value of x is _____ .

Q28.Sodium light of wavelengths 650 nm and 655 nm is used to study diffraction at a single slit of aperture 0. 5 mm. The distance between the slit and the screen is 2. 0 m. The separation between the positions of the first maxima of diffraction pattern obtained in the two cases is _____ ×10−5 m

Q28.In a Young's double slit experiment, an angular width of the fringe is 0. 35° on a screen placed at 2 m away for particular wavelength of 450 nm . The angular width of the fringe, when whole system is immersed in a medium of refractive index 7 , is 1 . The value of α is _____ . α 5

Q28.Two radioactive materials 𝐴 and 𝐵 have decay constants 25𝜆 and 16𝜆 respectively. If initially they have the 1 same number of nuclei, then the ratio of the number of nuclei of 𝐵 to that of A will be "𝑒" after a time 𝑎𝜆. The JEE Main 2022 (29 Jul Shift 2) JEE Main Previous Year Paper value of 𝑎 is _____ .

Q28.The graph between 1 and 1 for a thin convex lens in order to determine its focal length is plotted as shown in u v the figure. The refractive index of lens is 1. 5 and its both the surfaces have same radius of curvatures R. The value of R will be _____ cm. (Where u = object distance, v = image distance)

Q28.A light ray is incident, at an incident angle θ1 , on the system of two plane mirrors M1 and M2 having an inclination angle 75° between them (as shown in figure). After reflecting from mirror M1 it gets reflected back by the mirror M2 with an angle of reflection 30° . The total deviation of the ray will be _____ degree.

Q28.In the given figure of meter bridge experiment, the balancing length AC corresponding to null deflection of the galvanometer is 40 cm. The balancing length, if the radius of the wire AB is doubled, will be _____ cm. JEE Main 2022 (27 Jul Shift 2) JEE Main Previous Year Paper → +

Q28.A convex lens of focal length 20 cm is placed in front of convex mirror with principal axis coinciding each other. The distance between the lens and mirror is 10 cm. A point object is placed on principal axis at a distance of 60 cm from the convex lens. The image formed by combination coincides the object itself. The focal length of the convex mirror is _____ cm.

Q28.In Young's double slit experiment the two slits are 0. 6 mm distance apart. Interference pattern is observed on a screen at a distance 80 cm from the slits. The first dark fringe is observed on the screen directly opposite to one of the slits. The wavelength of light will be _____ nm.

Q28.The length of a given cylindrical wire is increased to double of its original length. The percentage increase in the resistance of the wire will be _____ %