Practice Questions

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.Five equal resistances are connected in a network as shown in figure. The net resistance between the points A and B is : JEE Main 2021 (26 Feb Shift 1) JEE Main Previous Year Paper (1) R (2) R2 (3) 3R2 (4) 2R

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 )

Q15.A constant magnetic field of 1 T is applied in the x > 0 region. A metallic circular ring of radius 1 m is moving with a constant velocity of 1 m s−1 along the x-axis. At t = 0 s, the centre O of the ring is at x = −1 m. What will be the value of the induced emf in the ring at t = 1 s ? (Assume the velocity of the ring does not change.) JEE Main 2021 (27 Aug Shift 2) JEE Main Previous Year Paper (1) 0 V (2) 2 V (3) 2π V (4) 1 V

Q15.An object is placed at the focus of concave lens having focal length f. What is the magnification and distance of the image from the optical centre of the lens? (1) 4 1 , f4 (2) 12 , f2 (3) Very high, ∞ (4) 1, ∞

Q15.For the given circuit the current 𝑖 through the battery when the key in closed and the steady state has been reached is (1) 10 A (2) 6 A (3) 25 A (4) 0 A

Q15.Two ions having same mass have charges in the ratio 1 : 2 . They are projected normally in a uniform magnetic field with their speeds in the ratio 2 : 3 . The ratio of the radii of their circular trajectories is, (1) 1 : 4 (2) 4 : 3 (3) 3 : 1 (4) 2 : 3

Q15. AC voltage V (t) = 20 sin ωt of frequency 50 Hz is applied to a parallel plate capacitor. The separation between the plates is 2 mm and the area is 1 m2 . The amplitude of the oscillating displacement current for the applied AC voltage is [Take ε0 = 8. 85 × 10−12 F m−1] JEE Main 2021 (20 Jul Shift 1) JEE Main Previous Year Paper (1) 21. 14 μA (2) 83. 37 μA (3) 27. 79 μA (4) 55. 58 μA

Q15.Two coherent light sources having intensity in the ratio 2x produce an interference pattern. The ratio Imax−Imin Imax+Imin will be (1) 2√2x (2) √2x x+1 2x+1 (3) 2√2x (4) √2x 2x+1 x+1 JEE Main 2021 (25 Feb Shift 1) JEE Main Previous Year Paper

Q15.An RC circuit as shown in the figure is driven by a AC source generating a square wave. The output wave pattern monitored by CRO would look close to : (1) (2) (3) (4)

Q15.The thickness at the centre of a plano convex lens is 3 mm and the diameter is 6 cm. If the speed of light in the material of the lens is 2 × 108 m s−1. The focal length of the lens is ___________. (1) 0. 30 cm (2) 15 cm (3) 1. 5 cm (4) 30 cm

Q15.Find the peak current and resonant frequency of the following circuit (as shown in figure). (1) 2 A and 50 Hz (2) 0. 2 A and 100 Hz (3) 2 A and 100 Hz (4) 0. 2 A and 50 Hz

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 time taken for the magnetic energy to reach 25% of its maximum value, when a solenoid of resistance R, inductance L is connected to a battery, is : (1) L ln5 (2) infinite R (3) R L ln2 (4) RL ln10

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.In Young's double slit arrangement, slits are separated by a gap of 0. 5 mm , and the screen is placed at a distance of 0. 5 m from them. The distance between the first and the third bright fringe formed when the slits o are illuminated by a monochromatic light of 5890 A is :- (1) 1178 × 10–9 m (2) 1178 × 10–6 m (3) 1178 × 10–12 m (4) 5890 × 10–7 m

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.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.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

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.Intensity of sunlight is observed as 0. 092 Wm−2 at a point in free space. What will be the peak value of magnetic field at that point ? (ε0 = 8. 85 × 10−12 C2 N−1 m−2) (1) 2. 77 × 10−8 T (2) 1. 96 × 10−8 T (3) 8. 31 T (4) 5. 88 T

Q15.Car B overtakes another car A at a relative speed of 40 m s−1 . How fast will the image of car B appear to move in the mirror of focal length 10 cm fitted in car A , when the car B is 1. 9 m away from the car A ? (1) 0. 1 m s−1 (2) 0. 2 m s−1 (3) 40 m s−1 (4) 4 m s−1

Q15.In the given circuit the AC source has ω = 100 rad s−1 . Considering the inductor and capacitor to be ideal, what will be the current I flowing through the circuit? (1) 5. 9 A (2) 6 A (3) 0. 94 A (4) 3. 16 A

Q15.At an angle of 30° to the magnetic meridian, the apparent dip is 45°. Find the true dip: (1) tan−1 √3 (2) tan−1 1 √3 (3) tan−1 2 (4) tan−1 √32 √3

Q15.Two capacitors of capacities 2C and C are joined in parallel and charged up to potential V . The battery is removed and the capacitor of capacity C is filled completely with a medium of dielectric constant K. The potential difference across the capacitors will now be: (1) V (2) V K+2 K (3) 3V (4) 3V K+2 K