Practice Questions

Q11.A charge Q is moving dl distance in the magnetic field B. Find the value of work done by B. (1) 1 (2) Infinite (3) Zero (4) −1 → x . A square loop of side d is placed with its edges along

Q12.Match List I with List II. List I List II (a) Rectifier (i) Used either for stepping up or stepping down the A.C. voltage (b)Stabilizer (ii) Used to convert A.C. voltage into D.C. voltage (c) Transformer(iii)Used to remove any ripple in the rectified output voltage Used for constant output voltage even when the input voltage (d)Filter (iv) or load current change Choose the correct answer from the options given below: (1) (a) −(ii), (b) −(iv), (c) −(i), (d) −(iii) (2) (a) −(ii), (b) −(i), (c) −(iv), (d) −(iii) (3) (a) −(ii), (b) −(i), (c) −(iii), (d) −(iv) (4) (a) −(iii), (b) −(iv), (c) −(i), (d) −(ii)

Q12.The correct relation between the degrees of freedom f and the ratio of specific heat γ is: (1) f = γ−12 (2) f = γ+12 (3) f = γ+12 (4) f = γ+11

Q12.For full scale deflection of total 50 divisions, 50 mV voltage is required in galvanometer. The resistance of galvanometer if its current sensitivity is 2 div / mA will be: (1) 1 Ω (2) 2 Ω (3) 5 Ω (4) 4 Ω

Q12.The relative permittivity of distilled water is 81. The velocity of light in it will be: (Given μr = 1) (1) 4. 33 × 107 m s−1 (2) 2. 33 × 107 m s−1 (3) 3. 33 × 107 m s−1 (4) 5. 33 × 107 m s−1

Q13.For the given circuit, comment on the type of transformer used : (1) Auxilliary transformer (2) Auto transformer (3) Step-up transformer (4) Step down transformer

Q13.A plane electromagnetic wave of frequency 100 MHz is traveling in a vacuum along the x−direction. At a → → particular point in space and time, B = 2. 0 × 10−8 ˆkT⋅ (where, ˆk is unit vector along z−direction) What is E at this point? (1) 0. 6ˆj V m−1 (2) 6. 0ˆk V m−1 (3) 6. 0ˆj V m−1 (4) 0. 6ˆk V m−1

Q13.The colour coding on a carbon resistor is shown in the given figure. The resistance value of the given resistor is: (1) (7500 ± 375)Ω (2) (5700 ± 285)Ω (3) (7500 ± 755)Ω (4) (5700 ± 375)Ω

Q13.In a circuit consisting of a capacitance and a generator with alternating emf, Eg = Egosinωt, VC and IC are the voltage and current. Correct phasor diagram for such circuit is JEE Main 2021 (22 Jul Shift 1) JEE Main Previous Year Paper (1) (2) (3) (4)

Q14.Your friend is having eye sight problem. She is not able to see clearly a distant uniform window mesh and it appears to her as nonuniform and distorted. The doctor diagnosed the problem as : (1) Astigmatism (2) Myopia with Astigmatism (3) Presbyopia with Astigmatism (4) Myopia and hypermetropia

Q14.Match List - I with List - II. List-I List-II (a) Source of microwave frequency (i) Radioactive decay of nucleus (b) Source of infrared frequency (ii) Magnetron (c) Source of Gamma Rays (iii) Inner shell electrons (d) Source of X -rays (iv) Vibration of atoms and molecules (v) LASER (vi) RC circuit Choose the correct answer from the options given below: (1) (a)-(ii), (b)-(iv), (c)-(vi), (d)-(iii) (2) (a)-(vi), (b)-(iv), (c)-(i), (d)-(v) (3) (a)-(vi), (b)-(v), (c)-(i), (d)-(iv) (4) (a)-(ii), (b)-(iv), (c)-(i), (d)-(iii)

Q14.The resistance of a conductor at 15°C is 16 Ω and at 100°C is 20 Ω. What will be the temperature coefficient of resistance of the conductor? (1) 0. 010°C−1 (2) 0. 033°C−1 (3) 0. 003°C−1 (4) 0. 042°C−1

Q14.Following plots show Magnetization ( 𝑀) vs Magnetising field ( 𝐻) and Magnetic susceptibility ( χ ) vs Temperature ( 𝑇) graph : Which of the following combination will be represented by a diamagnetic material? (1) ( b ) , ( c ) (2) ( b ) , ( d ) (3) ( a ) , ( d ) (4) ( a ) , ( c )

Q14.The given potentiometer has its wire of resistance 10 Ω. When the sliding contact is in the middle of the potentiometer wire, the potential drop across 2 Ω resistor is: (1) 10 V (2) 5 V (3) 40 9 V (4) 4011 V

Q14.In an ac circuit, an inductor, a capacitor and a resistor are connected in series with XL = R = XC. Impedance of this circuit is : (1) Zero (2) R (3) R√2 (4) 2R2 JEE Main 2021 (31 Aug Shift 1) JEE Main Previous Year Paper

Q14.A current through a wire depends on time as 𝑖= 𝛼0𝑡+ 𝛽𝑡2, where 𝛼0 = 20 A s-1 and 𝛽= 8 A s-2. Find the charge crossed through a section of the wire in 15 s . (1) 2250 C (2) 11250 C (3) 2100 C (4) 260 C

Q14.Red light differs from blue light as they have : (1) Different frequencies and different wavelengths (2) Different frequencies and same wavelengths (3) Same frequencies and same wavelengths (4) Same frequencies and different wavelengths

Q14.In a series LCR circuit, the inductive reactance (XL) is 10 Ω and the capacitive reactance (XC) is 4 Ω. The resistance (R) in the circuit is 6 Ω. The power factor of the circuit is : (1) 21 (2) 2√21 (3) 1 (4) √3 √2 2 JEE Main 2021 (18 Mar Shift 2) JEE Main Previous Year Paper

Q15.If the source of light used in a Young's double slit experiment is changed from red to violet: (1) consecutive fringe lines will come closer. (2) the fringes will become brighter. (3) the central bright fringe will become a dark (4) the intensity of minima will increase. fringe.

Q15.A coil is placed in a magnetic field →𝐵 as shown below : → A current is induced in the coil because 𝐵 is : (1) parallel to the plane of coil and increasing with (2) outward and increasing with time time (3) outward and decreasing with time (4) parallel to the plane of coil and decreasing with time + ^j cos𝑘𝑧- 𝜔𝑡 where ^i, ^j

Q15.The electric field in a plane electromagnetic wave is given by, E = 50 sin(500x −10 × 1010t) V m−1 . The velocity of an electromagnetic wave in this medium is: (Given c = the speed of light in vacuum). (1) 23 c (2) c (3) 2c (4) 23 c

Q15.A cell 𝐸1 of emf 6 V and internal resistance 2Ω is connected with another cell 𝐸2 of emf 4 V and internal resistance 8 Ω (as shown in the figure). The potential difference across points 𝑋 and 𝑌 is: (1) 10 . 0 V (2) 5 . 6 V (3) 2 . 0 V (4) 3 . 6 V

Q15.What should be the order of arrangement of de-Broglie wavelength of electron 𝜆e, an 𝛼-particle 𝜆α and proton 𝜆p given that all have the same kinetic energy ? (1) 𝜆𝑒= 𝜆𝑝= 𝜆𝛼 (2) 𝜆e < 𝜆p < 𝜆α (3) 𝜆e > 𝜆p > 𝜆α (4) 𝜆e = 𝜆p > 𝜆α

Q15.The refractive index of a converging lens is 1. 4. What will be the focal length of this lens if it is placed in a medium of same refractive index ? (Assume the radii of curvature of the faces of lens are R1 and R2 respectively) (1) 1 (2) Infinite (3) R1R2 (4) Zero R1−R2

Q15.An electron of mass me and a proton of mass mp = 1836 me are moving with the same speed. The ratio of their de Broglie wavelength λelectron will be : λproton (1) 1836 (2) 18361 (3) 918 (4) 1