Practice Questions

Q18.Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R Assertion A : The binding energy per nucleon is practically independent of the atomic number for nuclei of mass number in the range 30 to 170. Reason R : Nuclear force is short ranged. In the light of the above statements, choose the correct answer from the options given below (1) A is false but R is true (2) Both A and R are true and R is the correct explanation of A (3) Both A and R are true but R is NOT the correct (4) A is true but R is false. explanation of A

Q18. The current flowing through R2 is : (1) 3 2 A (2) 12 A (3) 1 3 A (4) 14 A

Q18.Consider the following radioactive decay process: 𝛼 𝛽- 𝛾 𝛼 𝛽+ 𝛾 218𝐴84 ⟶𝐴1 ⟶𝐴2 ⟶𝐴3 ⟶𝐴4 ⟶𝐴5 ⟶𝐴6 The mass number and the atomic number of A6 are given by: (1) 210 and 82 (2) 210 and 84 (3) 210 and 80 (4) 211 and 80

Q18.The current flowing through a conductor connected across a source is 2 A and 1. 2 A at 0oC and 100oC respectively. The current flowing through the conductor at 50oC will be _____ × 102 mA .

Q18.If a copper wire is stretched to increase its length by 20% . The percentage increase in resistance of the wire is _____%.

Q18.In the given circuit, the equivalent resistance between the terminal A and B is ____ Ω

Q18.A capacitor has capacitance 5 µF when its parallel plates are separated by air medium of thickness d. A slab of material of dielectric constant 1. 5 having area equal to that of plates but thickness d2 is inserted between the plates. Capacitance of the capacitor in the presence of slab will be ______ µF .

Q18.Name the logic gate equivalent to the diagram attached (1) NAND (2) AND (3) NOR (4) OR

Q19.The electric current in a circular coil of four turns produces a magnetic induction 32 T at its centre. The coil is unwound and is rewound into a circular coil of single turn, the magnetic induction at the centre of the coil by the same current will be : (1) 8 T (2) 4 T (3) 2 T (4) 16 T

Q19.Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R. Assertion A: Photodiodes are preferably operated in reverse bias condition for light intensity measurement. Reason R: The current in the forward bias is more than the current in the reverse bias for a 𝑝- 𝑛 junction diode. In the light of the above statement, choose the correct answer from the options given below : JEE Main 2023 (24 Jan Shift 1) JEE Main Previous Year Paper (1) A is false but R is true (2) Both A and R are true but R is NOT the correct 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

Q19.A current of 2 A flows through a wire of cross-sectional area 25. 0 mm2 . The number of free electrons in a cubic meter are 2. 0 × 1028 . The drift velocity of the electrons is _____ ×10−6 ms−1 (given, charge on electron = 1. 6 × 10−19C).

Q19.The output waveform of the given logical circuit for the following inputs 𝐴 and 𝐵 as shown below, is JEE Main 2023 (30 Jan Shift 1) JEE Main Previous Year Paper (1) (2) (3) (4)

Q19.When a resistance of 5 Ω is shunted with a moving coil galvanometer, it shows a full scale deflection for a current of 250 mA, however when 1050 Ω resistance is connected with it in series, it gives full scale deflection for 25 volt. The resistance of galvanometer is _________Ω.

Q19.For the given circuit, in the steady state, |VB −VD| = _____ V .

Q19.The half-life of a radioactive nucleus is 5 years. The fraction of the original sample that would decay in 15 years is : (1) 1 (2) 1 8 4 (3) 7 (4) 3 8 4

Q19.As shown in the figure, a current of 2 A flowing in an equilateral triangle of side 4√3 cm . The magnetic field at the centroid O of the triangle is : (Neglect the effect of earth’s magnetic field) (1) 4√3 × 10−4 T (2) 4√3 × 10−5 T (3) √3 × 10−4 T (4) 3√3 × 10−5 T

Q19.A long solenoid is formed by winding 70 turns cm−1 . If 2. 0 A current flows, then the magnetic field produced inside the solenoid is ______________. (µ0 = 4π × 10–7 T m A–1) (1) 1232 × 10–4 T (2) 176 × 10–4 T (3) 352 × 10–4 T (4) 88 × 10–4 T

Q19.Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R . Assertion A : Electromagnets are made of soft iron. Reason R : Soft iron has high permeability and low retentivity. In the light of above statements, choose the most appropriate answer from the options given below. (1) A is not correct but R is correct (2) A is correct but R is not correct (3) Both A and R are correct and R is the correct (4) Both A and R are correct but R is NOT the explanation of A correct explanation of A JEE Main 2023 (08 Apr Shift 2) JEE Main Previous Year Paper

Q19.Match the List I with List II List I List II AIntrinsic I Fermi-level near valence band Semiconductor Fermi-level at middle of valence and conduction B n-type semiconductor II band C p-type semiconductor III Fermi-level near conduction band DMetals IVFermi-level inside conduction band Choose the correct answer from the options given below: (1) (A) → I, (B) → II, (C) → III, (D) → IV (2) (A) → II, (B) → I, (C) → III, (D) → IV (3) (A) → II, (B) → III, (C) → I, (D) → IV (4) (A) → III, (B) → I, (C) → II, (D) → IV

Q19.The resistance of a wire is 5 Ω. Its new resistance in ohm, if stretched to 5 times of its original length will be : JEE Main 2023 (25 Jan Shift 2) JEE Main Previous Year Paper (1) 625 (2) 125 (3) 5 (4) 25

Q19.The magnitude of magnetic induction at mid-point O due to current arrangement as shown in figure will be . (1) μ0I (2) 0 2πa (3) μ0I (4) μ0I 4πa πa

Q19.Figure shows a part of an electric circuit. The potentials at points a, b and c are 30 V, 12 V and 2 V respectively. The current through the 20 Ω resistor will be, (1) 1. 0 A (2) 0. 4 A (3) 0. 6 A (4) 0. 2 A

Q19.Match List I with List II List – I List – II (Current configuration) (Magnetic field at point O ) + A I. B0 = μ0I4πr [π 2] JEE Main 2023 (25 Jan Shift 1) JEE Main Previous Year Paper B II. B0 = μ04 Ir C III. B0 = μ0I2πr [π −1] + D IV. B0 = μ0I4πr [π 1] Choose the correct answer from the option given below: (1) A-III, B-IV, C-I, D-II (2) A-I, B-III, C-IV, D-II (3) A-III, B-I, C-IV, D-II (4) A-II, B-I, C-IV, D-III

Q19.A zener diode of power rating 1 . 6 W is to be used as voltage regulator. If the zener diode has a breakdown of 8 V and it has to regulate voltage fluctuating between 3 V and 10 V The value of resistance 𝑅𝑠 for safe operation of diode will be (1) 10 Ω (2) 12 Ω (3) 13 . 3 Ω (4) 13 Ω

Q19.Two identical cells each of emf 1. 5 V are connected in series across a 10 Ω resistance. An ideal voltmeter connected across 10 Ω resistance reads 1. 5 V . The internal resistance of each cell is _____ Ω.