Tiêu đề 08. ELECTROMAGNETIC WAVES(H).pdf ✅

NEET REVISION 08. ELECTROMAGNETIC WAVES(H) NEET REVISION Date: March 18, 2025 Dura on: 1:00:00 Total Marks: 180 INSTRUCTIONS INSTRUCTIONS PHYSICS 1. A laser light of wavelength is used to weld Retina detachment. If a laser pulse of width and power is used the approxi‐ mate number of photons in the pulse are - [Take planck's constant ] [Q368986] (1) (2) (3) (4) 2. If the magnetic field in a plane electromagnetic wave is given by , then what will be expression for electric field? [Q369114] (1) (2) (3) (4) 3. A cube of edge has its edges parallel to and -axis of rectangular co-ordinate system. A uni‐ form electric field is parallel to -axis and a uniform magnetic field is parallel to - axis. The rate at which energy flows through each face of the cube is [Q368996] (1) all faces (2) zero in all faces (3) parallel to plane face and zero in others (4) parallel to plane face and zero in others 4. An wave radiates outwards from a dipole an‐ tenna, with as the amplitude of its electric field vector. The electric field which trans‐ ports significant energy from the source falls off as [Q368981] (1) (2) (3) Remains constant (4) 5. An electric field of is confined to a cir‐ cular area in diameter. If the field is in‐ creasing at the rate of , the magni‐ tude of magnetic field at a point from the center of the circle will be- [Q368934] (1) (2) (3) (4) 6. For plane electromagnetic waves propagating in the -direction, which one of the following com‐ bination gives the correct possible direction for and field respectively? [Q369069] (1) and (2) and (3) and (4) and 7. An object is placed in a medium of redfractive in‐ dex 3. An electromagnetic wave of intensity falls normally on the object and it is absorbed completely. The radiation pressure on the object would be (speed of light in free space ): [Q369020] 660 nm 60 ms 0.5 kW h = 6.62 × 10 −34JS 10 22 10 19 10 20 10 18 B→ = 3 × 10 −8 sin(1.6 × 10 3x + 48 × 10 10 t)^jT E→ = [9 sin(1.6 × 10 3 x + 48 × 10 10 t)k^V /m] E→ = [60 sin(1.6 × 10 3 x + 48 × 10 10 t)k^V /m] E→ = [3 × 10 −8 sin(1.6 × 10 3x + 48 × 10 10 t)^i V /m] E→ = [3 × 10 −8 sin(1.6 × 10 3x + 48 × 10 10 t)^j V /m] a x, y z E y x a 2 EB 2μ0 a 2 EB 2μ0 xy a 2 EB 2μ0 xy EM E0 E0 1 r 2 1 r 3 1 r 300 V /m 10 cm 20 V /m − s 15 cm 1.85 × 10 −17 T 1.85 × 10 −15 T 1.85 × 10 −16 T 1.85 × 10 −18 T z → E → B (2 ^i + 3 ^j) (^i + 2 ^j) (−2 ^i − 3 ^j) (3 ^i − 2 ^j) (3 ^i + 4 ^j) (4 ^i − 3 ^j) (^i + 2 ^j) (2 ^i − ^j) 6 × 10 8 W/m2 = 3 × 10 8 m/s
NEET REVISION (1) (2) (3) (4) 8. Match Column-I with Column-II of electromag‐ netic waves with corresponding wavelength range. Choose the correct answer from the op‐ tions given below. Column I Column II A. Microwave P. to B. Ultraviolet Q. C. -rays R. to D. Infra - red S. to [Q368962] (1) (2) (3) (4) 9. A plane wave is propagating along direc‐ tion. It has a wavelength of If electric field is in direction with the maximum magnitude of the equation for magnetic field is [Q369050] (1) (2) (3) (4) 10. A monochromatic beam of light has a frequency and is propagating along the direction . It is polarized along the direc‐ tion. The acceptable form for the magnetic field is: [Q369095] (1) (2) (3) (4) 11. An wave from air enters a medium. The electric fields are in air and in medium, where the wave number and frequency refer to their values in air. The medium is nonmag‐ netic. If and refer to relative permittivity of air and medium respectively, which of the fol‐ lowing options is correct? [Q369105] (1) (2) (3) (4) 12. Light with an energy flux of falls on a non-reflecting surface at normal incidence. If the surface has an area of the total mo‐ mentum delivered (for complete absorption) dur‐ ing is [Q369022] (1) (2) (3) (4) 13. The electric field in an electromagnetic wave is given as . Where and are angular frequency and velocity of electromagnetic wave respectively. The energy contained in a volume of will be (Given ) [Q369003] (1) (2) (3) (4) 14. A parallel-plate capacitor made of circular plates, each of radius , has a capaci‐ tance . The capacitor is connected to a supply with a (angular) frequency of Determine the amplitude of (in ) at a point from the axis between the plates. [Q369033] (1) 1.63 (2) 5.98 (3) 3.65 (4) 7.24 15. Match Column I with Column II. Choose the correct answer from the options given below. Column I Column II 2 Nm−2 18 Nm−2 6 Nm−2 36 Nm−2 400 nm 1 nm 1 nm 10 −3nm X 1 nm 700 nm 0.1 m 1 nm A − S, B − P, C − R, D − Q A − S, B − P, C − Q, D − R A − S, B − Q, C − P, D − R A − P, B − S, C − Q, D − R EM x 4 mm. y 60 V m−1 , B→ z = 2 × 10 −7 sin[ × 10 3 (x − 3 × 10 8 t)]^kT π 2 B→ x = 60 sin[ (x − 3 × 10 8 t)]^iT π 2 B→ z = 60 sin[ (x − 3 × 10 8 t)]k^T π 2 B→ z = 2 × 10 −7 sin[ (x − 3 × 10 8 t)]^kT π 2 v = × 10 12 Hz 3 2π ^i + ^j √2 k^ ( ) cos[10 4 ⋅ r→ − (3 × 10 12) t] E0 C ^i − ^j √2 (^i − ^j) √2 k^ cos[10 4 ⋅ r→ + (3 × 10 12) t] E0 C (^i + ^j) √2 cos[10 4 ⋅ r→ + (3 × 10 12) t] E0 C (^i − ^j) √2 (^i + ^j) √2 cos[10 4 ⋅ r→ + (3 × 10 12) t] E0 C (^i + ^j + k^) √3 (^i + ^j) √2 EM −→ E1 = E01x^ cos[2πv ( − t)] z c E→2 = E02x^ cos[k(2z − ct)] k v εr1 εr2 = 2 εr1 εr2 = εr1 εr2 1 4 = εr1 εr2 1 2 = 4 εr1 εr2 20 W/cm2 30 cm2 , 30 min 1.08 × 10 7 kg − m/s 108 × 10 4 kg − m/s 36 × 10 −4 kg − m/s 36 × 10 −5 kg − m/s E→ = 20 sin ω (t − ) ^jNC x −1 c ω c 5 × 10 −4 m3 ε0 = 8.85 × 10 −12C 2/Nm2 17.7 × 10 −13 J 88.5 × 10 −13 J 8.85 × 10 −13 J 28.5 × 10 −13 J R = 6.0 cm C = 100 pF 230 V a. c. 300 rad/s. B 10 −11 T 3.0 cm
NEET REVISION A. Gauss's law in Electrostatics P. B. Faraday's law Q. C. Gauss's law in magnetism R. D. Ampere- Maxwell Law S. [Q369127] (1) (2) (3) (4) 16. In a plane wave, the electric field oscillates sinusoidally at a frequency of and have an amplitude of The total average energy density of the electromagnetic field of the wave is [Use [Q368979] (1) (2) (3) (4) 17. A beam of light travelling along -axis is de‐ scribed by magnetic field What is the maximum electric and magnetic forces on a charge ., -particle moving along -axis with a speed of . (charge on electron ). [Q369075] (1) (2) (3) (4) 18. A plate of mass 10 is in equilibrium in air due to the force exerted by a light beam on the plate. Calculate power of the beam (in ). Assume that the plate is perfectly absorbing. [Q369024] (1) (2) (3) (4) 19. A bank of overhead arc lamps can produce a light intensity of in the space stimulator facility at NASA. Find the average momentum density of a total absorbing surface. [Q369028] (1) (2) (3) (4) 20. A parallel plate capacitor consists of two circular plates of radius . They are separated by a distance . If electric field between the ca‐ pacitor plates changes as find displacement current between the plates. [Q368923] (1) (2) (3) (4) 21. Calculate the amplitude of electric field pro‐ duced by the radiation coming from a bulb at a distance of . Assume that the effi‐ ciency of the bulb is and it is a point source. [Q369004] (1) (2) (3) (4) 22. If a source of electromagnetic radiation having power produces photons per second, the radiation belongs to a part of spectrum is (Take Planck constant [Q369126] (1) Micro waves (2) Gamma rays (3) Radio wave (4) Ultraviolet rays 23. If the total energy transferred to a surface in time is then the magnitude of the total momentum delivered to this surface for complete absorption will be [Q369010] (1) (2) (3) (4) 24. The mean intensity of radiation on the surface of the Sun is about . The rms value of the corresponding magnetic field is closest to [Q369007] (1) (2) (3) (4) 25. In an electromagnetic wave, the average energy density associated with magnetic field is [Q368974] (1) (2) (3) (4) 26. In the given electromagnetic wave sin , intensity of the associated light beam is (Given [Q368995] (1) 729 (2) 243 ∮ E→. d →l = − dφB dt ∮ B→. dA→ = 0 ∮ B→. d →l =μ0ic + μ0ε0 dφE dt ∮ E→. ds→ = qnet ε0 A − P, B − Q, C − R, D − S A − S, B − P, C − Q, D − R A − R, B − S, C − P, D − Q A − Q, B − R, C − S, D − P EM 5 × 10 10 Hz 50 V m−1 . ε0 = 8.85 × 10 −12C 2/Nm2 J ] 2.212 × 10 −10J m−3 4.425 × 10 −8J m−3 1.106 × 10 −8J m−3 2.212 × 10 −8J m−3 x Bz = 5 × 10 −9T sin ω(t − Y /C). i. e α y 3 × 10 8 m/s = 1.6 × 10 −19C 4.80 × 10 −17 N, 4.80 × 10 −17 N 4.85 × 10 −16 N, 5.6 × 10 −17 N 9.2 × 10 6 N, 9.2 × 10 3 N 4.8 × 10 −19 N, 4.8 × 10 −19 N g MW 30 MW 50 MW 10 MW 40 MW 2500 Wm−2 25 ft 8.33 × 10 −14 kgm−2 s −1 2.78 kgm−2 s −1 8.33 × 10 −6 kgm−2 s −1 2.78 × 10 −14 kgm−2 s −1 0.1 m 0.5 mm = 5 × 10 dE 13 dt V m×s 10.9 A 11.9 A 12.9 A 13.9 A 100 W 3 m 2.5% 3.07 V m−1 4.07 V m−1 5.07 V m−1 6.07 V m−1 15 kW 10 16 h = 6 × 10 −34 Js ) t 6.48 × 10 5 J, 1.58 × 10 −3 kg m/s 4.32 × 10 −3 kg m/s 2.16 × 10 −3 kg m/s 2.46 × 10 −3 kg m/s 10 8 W/m2 10 −2 T 1 T 10 −4 T 10 2 T Li 2 0 2 B2 2μ0 μ0B 2 2 μ0 2B2 Ey = 600 (ωt − kx)V m−1 (in W/m2) ε0 = 9 × 10 −12C 2N −1 m−2)