Practice Questions

Q25.A capacitor C1 of capacitance 5 μF is charged to a potential of 30 V using a battery. The battery is then removed and the charged capacitor is connected to an uncharged capacitor C2 of capacitance 10 μF as shown in figure. When the switch is closed charge flows between the capacitors. At equilibrium, the charge on the capacitor C2 is _____ μC.

Q25.The total internal energy of two mole monoatomic ideal gas at temperature T = 300 K will be _____ J. (Given R = 8. 31 J mol−1 ⋅K)

Q25.Two light beams of intensities 4I and 9I interfere on a screen. The phase difference between these beams on the screen at point A is zero and at point B is π. The difference of resultant intensities, at the point A and B, will be _____ I .

Q25.In a potentiometer arrangement, a cell gives a balancing point at 75 cm length of wire. This cell is now replaced by another cell of unknown emf. If the ratio of the emf's of two cells respectively is 3 : 2 , the difference in the balancing length of the potentiometer wire in above two cases will be _____ cm.

Q26.A 10 Ω, 20 mH coil carrying constant current is connected to a battery of 20 V through a switch. Now after switch is opened current becomes zero in 100 μs. The average e.m.f. induced in the coil is _____ V.

Q26.In a potentiometer arrangement, a cell of emf 1. 20 V gives a balance point at 36 cm length of wire. This cell is now replaced by another cell of emf 1. 80 V . The difference in balancing length of potentiometer wire in above conditions will be _____ cm.

Q26.An inductor of 0. 5 mH , a capacitor of 200 μF and a resistor of 2 Ω are connected in series with a 220 V ac source. If the current is in phase with the emf, the frequency of ac source will be ______ ×102 Hz .

Q26.A long cylindrical volume contains a uniformly distributed charge of density ρ C m−3 . The electric field inside the cylindrical volume at a distance x = 2ε0ρ m from its axis is _____ V m−1 . JEE Main 2022 (27 Jul Shift 1) JEE Main Previous Year Paper

Q26.Two electric dipoles of dipole moments 1 . 2 × 10-30 cm and 2 . 4 × 10-30 cm are placed in two difference uniform electric fields of strengths 5 × 104 N C-1 and 15 × 104 N C-1 respectively. The ratio of maximum 1 torque experienced by the electric dipoles will be 𝑥. The value of 𝑥 is _____ .

Q27.Two 10 cm long, straight wires, each carrying a current of 5 A are kept parallel to each other. If each wire experienced a force of 10−5 N , then separation between the wires 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.A capacitor of capacitance 500 𝜇F is charged completely using a de supply of 100 V. It is now connected to an inductor of inductance 50 mH to form an LC circuit. The maximum current in LC circuit will be _____ A.

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.In meter bridge experiment for measuring unknown resistance ' S ', the null point is obtained at a distance 30 cm from the left side as shown at point D. If R is 5. 6 kΩ, then the value of unknown resistance ' S ' will be _____ Ω.

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.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

Q29.A 8V Zener diode along with a series resistance 𝑅 is connected across a 20 V supply (as shown in the figure). If the maximum Zener current is 25 mA, then the minimum value of 𝑅 will be _____ Ω.

Q29.The energy band gap of semiconducting material to produce violet (wavelength = 4000 Å) LED is _____ eV. (Round off to the nearest integer).

Q29.In a Young's double slit experiment, a laser light of 560 nm produces an interference pattern with consecutive bright fringes' separation of 7 . 2 mm. Now another light is used to produce an interference pattern with consecutive bright fringes' separation of 8 . 1 mm. The wavelength of second light is _____ nm .

Q30.If the potential barrier across a p −n junction is 0. 6 V. Then the electric field intensity, in the depletion region having the width of 6 × 10−6 m , will be _____ ×105 N C−1

Q31.The number of radial and angular nodes in 4 d orbital are, respectively (1) 1 & 2 (2) 3 & 2 (3) 1 & 0 (4) 2 & 1

Q31.Consider the reaction 4HNO3l + 3KCls →Cl2g + NOClg + 2H2Og + 3KNO3s The amount of HNO3 required to produce110 . 0 g of KNO3 is (Given : Atomic masses of H, O, N and K are 1, 16, 14 and 39, respectively.) (1) 32 . 2 g (2) 69 . 4 g (3) 91 . 5 g (4) 162 . 5 g

Q31.The correct order of ionic size of N3−, Na+, F−, Mg2+ and O2− is : (1) Mg2+ < Na+ < F−< O2−< N3− (2) N3−< O2−< F < Na+ < Mg2+ (3) F−< Na+ < O2−< Mg2+ < N3− (4) Na+ < F−< Mg2+ < O2−< N3−

Q31.Element " E" belongs to the period 4 and group 16 of the periodic table. The valence shell electron configuration of the element, which is just above " E" in the group is (1) 2s22p4 (2) 3d10, 4s2, 4p4 (3) 3s23p4 (4) 4d10, 5s2, 5p4

Q31.The correct decreasing order of energy, for the orbitals having, following set of quantum numbers: (A) n = 3, 1 = 0, m = 0 (B) n = 4, l = 0, m = 0 (C) n = 3, l = 1, m = 0 (D) n = 3, 1 = 2, m = 1 (1) (D) > (B) > (C) > (A) (2) (B) > (D) > (C) > (A) (3) (C) > (B) > (D) > (A) (4) (B) > (C) > (D) > (A)