Practice Questions

Q49.The least count of a screw guage is 0.01 mm . If the pitch is increased by 75% and number of divisions on the circular scale is reduced by 50% , the new least count will be _____ ×10−3 mm

Q49.A tightly wound long solenoid carries a current of 1.5 A . An electron is executing uniform circular motion inside the solenoid with a time period of 75 ns . The number of turns per metre in the solenoid is … … -. [Take mass of electron me = 9 × 10−31 kg, charge of electron |qe| = 1.6 × 10−19C, μ0 = 4π × 10−7 N , 1 ns = 10−9 A2 s]

Q49.A tube of length 1 m is filled completely with an ideal liquid of mass 2 M , and closed at both ends. The tube is rotated uniformly in horizontal plane about one of its ends. If the force exerted by the liquid at the other end is F then angular velocity of the tube is in SI unit. The value of α is __________. √FαM

Q49.Three conductors of same length having thermal conductivity k1, k2 and k3 are connected as shown in figure. Area of cross sections of 1st and 2nd conductor are same and for 3rd conductor it is double of the 1st conductor. The temperatures are given in the figure. In steady state condition, the value of θ is _______ ∘C. (Given : k1 = 60Js−1 m−1 K−1, k2 = 120Js−1 m−1 K−1, k3 = 135Js−1 m−1 K−1 ) ∣ ∣∣ 2025 (22 Jan Shift 1) JEE Main Previous Year Paper

Q49.An ideal gas initially at 0∘C temperature, is compressed suddenly to one fourth of its volume. If the ratio of specific heat at constant pressure to that at constant volume is 3/2, the change in temperature due to the thermodynamic process is _____ K.

Q49.A satellite of mass M is revolving around earth in a circular orbit at a height of R from earth surface. The 2 3 angular momentum of the satellite is . The value of x is ______ , where M and R are the mass and M√GMRx radius of earth, respectively. ( G is the gravitational constant)

Q49.A container of fixed volume contains a gas at 27∘C. To double the pressure of the gas, the temperature of gas should be raised to ______ ∘C.

Q49.Two cars P and Q are moving on a road in the same direction. Accleration of car P increases linearly with time whereas car Q moves with a constant accleration. Both cars cross each other at time t = 0, for the first time. The maximum possible number of crossing(s) (including the crossing at t = 0) is ________.

Q49.Two iron solid discs of negligible thickness have radii R1 and R2 and moment of intertia I1 and I2 , respectively. For R2 = 2R1 , the ratio of I1 and I2 would be 1/x, where x = ________ -

Q50.A physical quantity Q is related to four observables a, b, c, d as follows : Q = ab4cd where, a = (60 ± 3)Pa; b = (20 ± 0.1)m; c = (40 ± 0.2)Nsm−2 and d = (50 ± 0.1)m , then the percentage error in Q is x , where x = ________ . 1000

Q50.Two long parallel wires X and Y , separated by a distance of 6 cm , carry currents of 5A and 4A, respectively, in opposite directions as shown in the figure. Magnitude of the resultant magnetic field at point P at a distance 2025 (22 Jan Shift 2) JEE Main Previous Year Paper of 4 cm from wire Y is x × 10−5 T. The value of x is__________ . Take permeability of free space as μ0 = 4π × 10−7SI units.

Q50.A wire of resistance 9Ω is bent to form an equilateral triangle. Then the equivalent resistance across any two vertices will be _____ ohm.

Q50.The volume contraction of a solid copper cube of edge length 10 cm , when subjected to a hydraulic pressure of 7 × 106 Pa, would be ____ mm3 . (Given bulk modulus of copper = 1.4 × 1011 N m−2 )

Q50.The maximum speed of a boat in still water is 27 km/h. Now this boat is moving downstream in a river flowing at 9 km/h. A man in the boat throws a ball vertically upwards with speed of 10 m/s. Range of the ball as observed by an observer at rest on the river bank, is _______ cm. (Take g = 10 m/s2 )

Q50.Acceleration due to gravity on the surface of earth is ' g '. If the diameter of earth is reduced to one third of its original value and mass remains unchanged, then the acceleration due to gravity on the surface of the earth is … … g.

Q50.At steady state the charge on the capacitor, as shown in the circuit below, is μC.

Q50.The moment of inertia of a solid disc rotating along its diameter is 2.5 times higher than the moment of inertia of a ring rotating in similar way. The moment of inertia of a solid sphere which has same radius as the disc and rotating in similar way, is n times higher than the moment of inertia of the given ring. Here, $\mathrm{n}=_________ Consider all the bodies have equal masses.

Q50.A particle is projected at an angle of 30∘ from horizontal at a speed of 60 m/s. The height traversed by the particle in the first second is h0 and height traversed in the last second, before it reaches the maximum height, is h1 . The ratio h0 : h1 is _________ [Take, g = 10 m/s2 ]

Q50.A force f = x2y^i + y2^j acts on a particle in a plane x + y = 10. The work done by this force during a displacement from (0, 0) to (4 m, 2 m) is Joule (round off to the nearest integer)

Q51. List - I List - II (Complex) (Hybridisation & Magnetic characters) (A) [MnBr4]2− (I) d2s3 & diamagnetic Match List - I with List - II. (B) [FeF6]3− (II) sp3 d2 & paramagnetic (C) [Co(C2O4)3]3− (III) sp3 & diamagnetic (D) [Ni(CO)4] (IV) sp3 & paramagnetic Choose the correct answer from the options given below : (1) (A) −(IV), (B) −(II), (C) −(I), (D) −(III) (2) (A) −(III), (B) −(I), (C) −(II), (D) −(IV) (3) (A) −(IV), (B) −(I), (C) −(II), (D) −(III) (4) (A) −(III), (B) −(II), (C) −(I), (D) −(IV)

Q51.Identify the products [A] and [B], respectively in the following reaction : 2025 (23 Jan Shift 2) JEE Main Previous Year Paper (1) (2) (3) (4) −−

Q51.The carbohydrate "Ribose" present in DNA, is A. A pentose sugar B. present in pyranose from C. in "D" configuration D. a reducing sugar, when free E. in ∝-anomeric form Choose the correct answer from the 2025 (24 Jan Shift 1) JEE Main Previous Year Paper options given below: (1) A, D and E Only (2) A, C and D Only (3) A, B and E Only (4) B, D and E Only

Q51.For hydrogen atom, the orbital/s with lowest energy is/are : (A) 4 s (B) 3px (C) 3 dx2−y2 (D) 3 dz2 (E) 4pz Choose the correct answer from the options given below : (1) (B), (C) and (D) only (2) (A) and (E) only (3) (A) only (4) (B) only

Q51.Concentrated nitric acid is labelled as 75% by mass. The volume in mL of the solution which contains 30 g of nitric acid is ____. Given : Density of nitric acid solution is 1.25 g/mL . (1) 40 (2) 32 (3) 45 (4) 55

Q51.Radius of the first excited state of Helium ion is given as : a0 → radius of first stationary state of hydrogen atom. (1) r = 4a0 (2) r = 2a0 (3) r = a02 (4) r = a04