NEET UG Physics Electromagnetic Waves MCQs

(11) Electric field in an electromagnetic wave is given by E=50 sinω(t-x/c) NC^-1 .Intensity of this wave is ___________ Wm^-2
(A) 50 (B) 1.1×10⁸ (C) 3.3 (D) 5.5×10^-19

(12) The amplitude of the electric field in a parallel beam of light of intensity 2.0Wm^-2 is _______
(A) 38.8NC^-1 (B)19.4NC^-1 (C) 9.7NC^-1 (D) None of these.

(13) Speed of electromagnetic wave is the same
(A) for all wavelengths (B) in all media
(C) for all intensities (D) for all frequencies

(14) The maximum electric field in a plane electromagnetic wave is 900NC^-1 . The wave is going in the x direction and the electric field is in the y direction. The maximum magnetic field in the wave is ____________T
(A)3×10^-8 (B) 3×10^-6 (C) 27×10^-6 (D) 27×10¹⁰

(15) Electromagnetic waves are produced by
(A) a static charge (B) a moving charge
(C) an accelerating charge (D) chargeless particles

(16) Maxwells equations are derived from the laws of___________
(A) electricity (B) magnetism
(C) both electricity and magnetism (D) mechanics

(17) Which of the following electromagnetic waves has the longest wavelength?
(A) Radio waves (B) Infrared radiations
(C) x rays (D) visible rays

(18) Which of the following electromagnetic waves has the highest frequency?
(A) radio waves (B) micro waves (C) r rays (D) x rays

(19) Which of the following electromagnetic waves is used in telecommunication?
(A) radio waves (B) visible radiations
(C) ultraviolet rays (D) micro waves

(49) The velocity of light in vaccum can be changed by changing____
(A) frequency (B)wavelength (C)amplitude (D) none of these

(50) An electromagnetic wave going through vaccum is described by E=E_o sin(kx- ω t) then B=B_o sin(kx- ω t) then
(A) E₀B₀= ω k (B) E₀k = B₀ ω (C) E₀ ω = B₀k (D)none of these

(51) If the wavelength of light is 4000° A then the number of waves in 1mm length will be___
(A)2.5 (B)2500 (C)250 (D)25000

(52) The SI unit of displacement current is_________
(A) coulomb (B)henry (C) ampere (D)faraday

(53) The electromagnetic waves do not transport_______
(A) energy (B) charge (C)momentum (D)information

(54) An electric charge oscillating with a frequency of 1kilo cycles/s can radiate electromagnetic waves of wavelength
(A) 100km (B)200km (C) 300km (D)400km

(55) The frequency 1057MHz of radiation arising from two close energy levels in hydrogen belongs to_____
(A) radio waves (B)infrared waves (C)micro waves (D) γ rays

(71) Unit of  l oC is same as that of
(A)current (B)resistance (C)electric charge (D) velocity

(72) In electromagnetic spectrum, the visible light lie between
(A) radiowaves and microwaves
(B) ultraviolet rays and infrared rays
(C) ultraviolet rays and x rays
(D) infrared rays and microwaves

(73) Which of the following statements is not true in case of electromagnetic waves?
(A) they are light waves (B)theay are transverse waves
(C) propagates through space (D) they are longitudinal waves

(74) The oscillating electric and magnetic field vectors of an electromagnetic waves far away from source are oriented along
(A) Mutually perpendicular direction and differ in phase by 90°
(B) Mutually perpendicalar and in same phase
(C) In same direcfi on and in same phase
(D) In same divecfi on and differ in phaseby 90°

(75) Which of the following option of electromagnetic waves is in order of increasing frequency ?
(A) microwaves, ultraviolet rays, x rays
(B) gamma rays, ultraviolet rays, radiowaves
(C) radiowaves, visible light, infrared rays
(D) gamma rays, visible light, ultraviolet rays

(90) Which of the following electromagnetic wave has the least frequency?
(A) radiowave (B) infrared radiation (C)microwave (D)x rays

(91) Which of the following electromagnetic wave has the least wavelength?
(A) rradiowave (B)visible wave (C) ultraviolet rays (D) microwaves

(92) Which of the following waves are not transverse in nature?
(A) light emitted from a sodium lamp
(B) sound waves travelling in air
(C) xrays from an x ray machine
(D) microwaves used in radar

(93) An electromagnetic wave
(A) can be deflected by electric field
(B) can be deflected by magnetic field
(C) can be deflected bye both electric and magnetic field
(D) none of these

(94) When an electromagnetic wave encounters a dielectric medium, the transmitted wave has
(A) same frquency but different amplitude
(B) same amplitude but different frequency
(C) same frequency and amplitude
(D) different frequency and amplitude

ANSWERS