Description : Which one of the following radiations has the most energetic photon? a) T.V. waves b) Micro waves c) X-rays d) - rays
Last Answer : d) - rays
Description : Pair production can be studied with a) Ultraviolet rays b) X-rays c) Microwaves d) -rays
Last Answer : d) -rays
Description : Which one of the following phenomena can be studied with -rays a) Photoelectric effect b) Compton effect c) Pair production d) All of the above
Last Answer : a) Photoelectric effect
Description : By the transition of inner shell electrons in heavy atoms, high energy photons are emitted which are a) gamma rays b) X-rays c) radio waves d) photon rays
Last Answer : b) X-rays
Description : Electromagneticwaves are refractedwhen they a. pass into a medium of different dielectric constant b. are polarized at right angles to the direction of propagation c. encounter a perfectly conducting plane d. pass through a small slot in a conducting plane
Last Answer : a. pass into a medium of different dielectric constant
Description : The X-rays emitted in inner shell transitions are called _____ as their energy depends upon the type of target material. a) gamma rays b) special X-rays c) Characteristic X-rays d) continuous X-rays
Last Answer : c) Characteristic X-rays
Description : Waves which need a material medium for their propagation are called
Last Answer : mechanical waves.
Description : .In electromagneticwaves,polarization a. is caused by reflection b.isdue to the transversenature ofthewaves c. results from the longitudinal nature of the waves d. is always vertical in an isotropic medium
Last Answer : b.isdue to the transversenature ofthewaves
Description : In human flesh, the three light elements which predominate, and allow greater amount of incident X-rays to pass through them are a) oxygen, nitrogen , hydrogen b) oxygen, hydrogen, helium c) oxygen, hydrogen, carbon d) carbon, nitrogen, oxygen
Last Answer : c) oxygen, hydrogen, carbon
Description : Thehigherthe index number a. the higher the speed of light b. the lower the speed of light c. has no effect on the speed of light d. the shorter the wavelength propagation
Last Answer : a. the higher the speed of light
Description : Which of the following waves are diffracted by an obstacle of size 1 cm? (a) Light waves (b) Sound waves (c) Ultrasonic waves (d) X-rays
Last Answer : Ans:(c)
Description : All of the following are electromagnetic radiations except-----? A. Red light B. Sound waves (Answer) C. X-Rays D. Photon
Last Answer : B. Sound waves (Answer)
Description : The term "laminar flow" is most often associated with the description of: w) conduction of sound by waves x) current flow in transistors y) effects of viscosity of liquids z) passage of light rays through a liquid
Last Answer : ANSWER: Y -- EFFECTS OF VISCOSITY OF LIQUIDS
Description : ________ dispersion is caused by the difference in the propagation times of light rays that take different paths down a fiber. a. Material dispersion b. Wavelength dispersion c. Modal dispersion d. Delay dispersion
Last Answer : c. Modal dispersion
Description : ______ dispersion is caused by the difference in the propagation times of light rays that take different paths down a fiber. ∙ a. Material dispersion ∙ b. Wavelength dispersion ∙ c. Modal dispersion
Last Answer : ∙ c. Modal dispersion
Description : Which of the following statements is not true with respect to microwaves? (A) Electromagnetic waves with frequencies from 300 GHz to 400 THz. (B) Propagation is line-of-sight. (C) Very ... waves cannot penetrate walls. (D) Use of certain portions of the band requires permission from authorities.
Last Answer : (A) Electromagnetic waves with frequencies from 300 GHz to 400 THz.
Description : Light waves can cause photoelectric emission in a) Metals b) Alkali metals c) Insulators d) None of the above
Last Answer : c) Insulators
Description : Which one of the following scientists regarded light as electromagnetic waves? a) Newton b) Galileo c) de Broglie d) Maxwell
Last Answer : d) Maxwell
Description : X-rays that are emitted in all directions and with a continuous range of frequencies are known as a) characteristic X-rays b) continuous X-rays c) scattered X-rays d) stimulated X-rays.
Last Answer : b) continuous X-rays
Description : The reverse process of photo-electric effect is called: a) Annihilation of matter b) Compton effect c) Pair production d) X-rays
Last Answer : d) X-rays
Description : X-rays were discovered by: a) Roentgen b) Becquerel c) Marie Curie d) Van Lave
Last Answer : a) Roentgen
Description : X-rays can penetrate several ____ into a solid matter. a) millimeters b) meters c) centimeters d) kilometers
Last Answer : c) centimeters
Description : For the production of X-rays, the electrons which strike with the target are a) slow moving b) fast moving c) vibrational electrons d) free electrons
Last Answer : b) fast moving
Description : The practical application of electrostatic is: (a) Photocopier (b) X-rays machines (c) Laser (d) All of above 42. The electric field lines emerge from the charges in: (a) Three dimensions (b) Two dimensions (c) One dimension (d) All of above
Last Answer : (a) Photocopier
Description : Distancesnearthe skip distance should beused forthe sky-wave propagation a. to avoid tilting b.topreventsky-wave andupper rayinterference c. to avoid the Faraday effect d. so as nor to exceed the critical frequency
Last Answer : b.topreventsky-wave andupper rayinterference
Description : Indicatewhich one ofthe followingterms appliestotroposcatter propagation: a. SIDs b.Fading c. Atmospheric storms d. Faraday rotation
Last Answer : b.Fading
Description : Moving electric charge produces - (1) magnetic field (2) sound waves (3) light rays (4) heat waves
Last Answer : (1) magnetic field Explanation: An electric charge always produces an electric field, regardless of speed, and a moving charge generates a magnetic field. An electric current passing through a conductor produces a magnetic field because it has many charges in motion.
Description : Moving electric charge produces : (1) magnetic field (2) sound waves (3) light rays (4) heat waves
Last Answer : magnetic field
Description : The absorption ofradiowaves bythe atmosphere depends on a. their frequency b. their distance from the transmitter c. the polarization of the waves d. the polarization of the atmosphere
Last Answer : a. their frequency
Description : In annihilation of matter the photons produced fly off at the speed of a) Light b) Sound c) Twice the speed of light d) None
Last Answer : a) Light
Description : ___________ remain undeflected in a magnetic field a) β particles b) α particles c) γ rays d) Proton beams
Last Answer : c) γ rays
Description : The waves used for sending signals to the satellite from ground station are _____. A. Ultraviolet rays B. X-rays C. Sound waves D. Micro waves
Last Answer : ANSWER: D
Description : Which of the following does NOT travel in a vacuum? w) radio waves x) gamma rays y) magnetic waves z) sound waves
Last Answer : ANSWER: Z -- SOUND WAVES
Description : The operation of a transistor requires ______ (a) Emitter is heated (b) base is heated (c) collector be heated (d) none of above
Last Answer : (d) none of above
Description : The propagation of sound waves in a gas involves – (1) Adiabatic compression and rarefaction (2) Isothermal compression and rarefaction (3) Isochoric compression and rarefaction (4) Isobaric compression and rarefaction
Last Answer : (1) Adiabatic compression and rarefaction Explanation: Sound is a mechanical wave that is an oscillation of pressure transmitted through a solid, liquid, or gas, composed of frequencies within the ... . Through solids, however, it can be transmitted as both longitudinal waves and transverse waves.
Last Answer : (1) Adiabatic compression and rarefaction Explanation: Sound is a mechanical wave that is an oscillation of pressure transmitted through a solid, liquid, or gas, composed of frequencies within ... is transmitted through gases, plasma, and liquids as longitudinal waves, also called compression waves.
Description : Sound waves propagation in air exemplifies an __________ process. (A) Adiabatic (B) Isothermal (C) Isometric (D) None of these
Last Answer : (A) Adiabatic
Description : The propagation of sound waves in a gas involves (1) adiabatic compression and rarefaction (2) isothermal compression and rarefaction (3) isochoric compression and rarefaction (4) isobaric compression and rarefaction
Last Answer : adiabatic compression and rarefaction
Description : .Diffractionof electromagneticwaves a. is caused by reflections from the ground b. arises only with spherical wavefronts c. will occur when the waves pass through a large slot d.may occuraroundthe edge of asharpobstacle
Last Answer : d.may occuraroundthe edge of asharpobstacle
Description : FrequenciesintheUHFrange normallypropagate bymeans of a. ground waves b. sky waves c. surface waves d.spacewaves
Last Answer : d.spacewaves
Description : The concept that particles can behave like waves was given by a) Compton b) De-Broglie c) G.P. Thomson d) Germer
Last Answer : b) De-Broglie
Description : de Broglie’s relation for matter waves was experimentally verified by: a) Davisson b) Germer c) G.P. Thomson d) All the these
Last Answer : c) G.P. Thomson
Description : The concept of matter waves was introduced by a) Davisson and Germer b) de Broglie c) Einstein d) Schrodinger
Last Answer : b) de Broglie
Description : In a half wave rectifier the rms value of AC component of the waves (a) Zero (b) Equal to DC value (c) More than DC value (d) Less than DC value
Last Answer : b) Equal to DC value
Description : If a material object moves with the speed of light ‘c’ its mass becomes a) equal to its rest mass b) Four times of its rest mass c) Double of its rest mass d) Infinite
Last Answer : d) Infinite
Description : The unit of absolute permittivity of a medium is
Last Answer : Farad/ metre
Description : The electric force between two charges placed in air is 2 Newton. When placed in a medium of ∈r = 80, the force reduced to: (a) 0.029 N (b) 0.025 N (c) 0.03 N (d) 0.04 N
Last Answer : (b) 0.025 N