Description : Black body radiation spectrum is an example of a) band spectra b) continuous spectra c) discrete spectra d) atomic spectra
Last Answer : b) continuous spectra
Description : The photoelectric effect is a demonstration of: w) the wave nature of light x) the particle nature of light y) Compton scattering z) the continuous spectrum of radiation
Last Answer : ANSWER: X -- THE PARTICLE NATURE OF LIGHT
Description : When a fast charged particle traverses a dielectric medium at a velocity exceeding the velocity of light in that medium, radiation is emitted. This radiation is known as: w) point radiation x) Cerenkov radiation y) Synchrotron radiation z) Bremsstrahlung
Last Answer : ANSWER: X -- CERENKOV RADIATION
Description : In order to obtain spectrum from the emitted radiation, the atomic gas or vapour must be excited at a) much less than atmospheric pressure b) much high than atmospheric pressure c) atmospheric pressure d) high pressure and temperature
Last Answer : a) much less than atmospheric pressure
Description : Line spectrum is obtained on the screen in the form of lines if the slit in front of the source is a) narrow square b) broad square c) narrow rectangle d) broad rectangle
Last Answer : c) narrow rectangle
Description : When a solid material is heated, it always: w) emits a discrete radiation spectrum x) glows red y) emits a continuous radiation spectrum z) emits only visible radiation
Last Answer : ANSWER: Y -- EMITS A CONTINUOUS RADIATION SPECTRUM
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 : 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 only series which lies in the visible region of the electromagnetic spectrum is a) Paschen series b) Lyman series c) Balmer series d) Pfund series
Last Answer : b) Lyman series
Description : The fact that the spectrum of any element contains wavelengths that exhibit definite regularities was ` utilized in the second half of the _______in identifying different elements. a) 16th century b) 17th century c) 18th century d) 19th century
Last Answer : d) 19th century
Description : Atomic Spectra is an example of a) discrete spectra b) band spectra c) atomic spectra d) continuous spectra
Last Answer : a) discrete spectra
Description : Molecular spectra is an example of a) continuous spectra b) discrete spectra c) band spectra d) atomic spectra
Last Answer : c) band spectra
Description : Anincidentraycan be defined as a. a light ray reflected from a flat surface b. alight raydirectedtowardasurface c. a diffused light ray d. a light ray that happens periodically
Last Answer : b. alight raydirectedtowardasurface
Description : The ejection of electrons when a metal surface is irradiated is called (a) Black body radiation (b) Photoelectric effect (c) Zeeman effect (d) Atomic spectrum
Last Answer : Ans:(b)
Description : Indicatewhich one ofthe followingreasonsforthe use of a groundscreenwith antennasisfalse: a. Impossibility of a good ground connection b. Provision of an earth for the antenna c.Protectionofpersonnelworkingunderneath d. Improvement of the radiation pattern of the antenna
Last Answer : c.Protectionofpersonnelworkingunderneath
Description : Laser is the acronym for a) Light Amplification by Stimulated Emission of Radiation b) Light Amplification by Spontaneous Emission of Radiation c) Light Amplified by Stimulated Emission of Radiation d) Light Amplification by Standard Emission of Radiation
Last Answer : a) Light Amplification by Stimulated Emission of Radiation
Description : The branch of physics that deals with the investigation of wavelengths of electro magnetic radiation emitted or absorbed by atoms is known as a) spectroscopy b) astroscopy c) radioscopy d) stereoscopy
Last Answer : a) spectroscopy
Description : Which of the following phenomena provides a convincing proof for wave nature of radiation a) Reflection b) Refraction c) Polarization d) Interference and diffraction
Last Answer : d) Interference and diffraction
Description : The results obtained by the Balmer were formulated, in 1896, by a) Theodore Lyman b) F. S. Brackett c) J.R.Rydberg d) J.J.Balmer
Last Answer : c) J.R.Rydberg
Description : A three dimensional image is obtained by a)Electron microscope b) Scanning electron microscope c) Magnetic imaging d)None of these
Last Answer : b) Scanning electron microscope
Description : Three resistors of resistance R are connected in various ways, which of the following cannot be obtained? a. 3R ohm b. 2R/4 ohm c. R/3 ohm d. 2R/3 ohm
Last Answer : b. 2R/4 ohm
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 : The region of the electromagnetic spectrum immediately above the frequencies to which the human eye is sensitive is called: w) ir x) ultra-violet y) rf z) gamma ray
Last Answer : ANSWER: X -- ULTRA-VIOLET
Description : The nature of X-RAY spectrum is -Science
Last Answer : answer:
Description : In which region of electromagnetic spectrum does the Lyman series of hydrogen atom lie? (1) Visible (2) Infrared (3) Ultraviolet (4) X-ray
Last Answer : (3) Ultraviolet
Description : Most fiber optic light sources emit light in which spectrum? ∙ A. visible ∙ B. infrared ∙ C. ultraviolet ∙ D. X-ray
Last Answer : B. infrared
Description : Most fiber-optic light sources emit light in which spectrum? ∙ a. Visible ∙ b. Infrared ∙ c. Ultraviolet ∙ d. X-ray
Last Answer : ∙ b. Infrared
Description : In which region of electromagnetic spectrum does the Lyman series of hydrogen atom lie ? (1) Visible (2) Infrared (3) Ultraviolet (4) X-ray
Last Answer : Ultraviolet
Description : The conventional current is due to the flow of a. atoms and molecules b. positive charges c. negative charges d. both b and c
Last Answer : b. positive charges
Description : In liquids and gases the current is due to the motion a. negative charges b. positive charges c. both negative and positive charges d. neutral particles
Last Answer : c. both negative and positive charges
Description : A device based on photo electric effect is called a) Photo sensitive b) Photo diode c) Photo synthesis d) Photo cell
Last Answer : d) Photo cell
Description : Can Energy of a photon be any value along a continuous spectrum of energies?
Last Answer : I believe it can - the energy of a photon is the product of thefrequency and Plank's constant - and as far as I know, thefrequency is not quantized.
Description : The emission in which the atom emits a photon of energy hf = E2 – E1 , in any arbitrary direction is a) Spontaneous emission b) stimulated emission c) induced emission d) both a & c
Last Answer : d) both a & c
Description : The incident photon absorbed by an atom in the ground state E1, thereby leaving the atom in the excited state E2 , is a) spontaneous absorption b) stimulated absorption c) induced absorption d) both b & c
Last Answer : d) both b & c
Description : An OP-AMPs can amplify _______ (a) D.C (b) A.C (c) both A.C & D.C (d) none of above
Last Answer : b) A.C
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 : Whenmicrowave signalsfollowthe curvatureofthe earth,thisisknownas a. the Faraday effect b.ducting c. tropospheric scatter d. ionospheric reflection
Last Answer : b.ducting
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 : Thevelocityfactor of a transmissionline a. depends on the dielectric constant of the material used b. increases the velocity along the transmission line c. is govern by the skin effect d. is higher for a solid dielectric than for air
Last Answer : a. depends on the dielectric constant of the material used
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 : Photoelectric effect was discovered by a) Einstein b) G.P.Thomson c) Hallwachs d) Lenard
Last Answer : a) Einstein
Description : In forward bias, the width of potential barrier __________ (a) Increases (b) decreases (c) remains same (d) no effect
Last Answer : (b) decreases
Description : The region of the electromagnetic spectrum immediately above the frequencies to which the human eye is sensitive is called: A. I r B. ultra-violet C. r f D. gamma ray
Last Answer : B. ultra-violet
Description : The phenomenon of producing emf in the coil due to change of current in the coil itself is called: a. mutual induction b. self-induction c. self-inductance d. mutual inductance
Last Answer : d. mutual inductance
Description : In a certain spectrum produced by a glass prism of dispersive power `0.0305,` it is found that the refractive index for the red ray is `1.645.`and tha
Last Answer : In a certain spectrum produced by a glass prism of dispersive power `0.0305,` it is found that ... . What is the refractive index for the yellow ray?
Description : When white light passes through a glass prism we get a spectrum on the other side of the prism. In the emergent beam the ray which is deviated least is - (1) the violet ray (2) the red ray (3) the green ray (4) the blue ray
Last Answer : (2) the red ray Explanation: Red is deviated the least and violet the most.
Description : Fleming's left hand rule is used to find (a) direction of magnetic field due to current carrying conductor (b) direction of flux in a solenoid (c) direction of force on a current carrying conductor in a magnetic field (d) polarity of a magnetic pole
Last Answer : (c) direction of force on a current carrying conductor in a magnetic field
Description : The reverse current through semiconductor diode is due to (a) Minority carrier (b) majority carrier (c) electrons (d) holes
Last Answer : (a) Minority carrier
Description : Forward current through a semi-conductor diode circuit is due to ________ (a) Minority carriers (b) majority carriers (c) holes (d) electrons
Last Answer : (b) majority carriers
Description : The strain due to tensile stress is : a) Compressive strain b) Shear strain c) Volumetric strain d) Tensile strain
Last Answer : d) Tensile strain