Description : The Laser is a beam of radiations which are – (1) Non-coherent and monochromatic (2) Coherent and monochromatic (3) Non-coherent and non-monochromatic (4) Coherent and non-monochromatic
Last Answer : (2) Coherent and monochromatic Explanation: Laser, an acronym for Light Amplification by Stimulated Emission of Radiation, creates a radiation beam that is coherent (in-phase). In a coherent light ... results in a radiation beam of great intensity. It normally produces only one or two wavelengths.
Description : The Laser is a beam of radiations which are (1) Non-coherent and monochromatic (2) Coherent and monochromatic (3) Non-coherent and non-monochromatic (4) Coherent and non-monochromatic
Last Answer : Coherent and monochromatic
Description : The characteristic that distinguishes a laser beam from an ordinary light beam is: w) the greater frequency of the laser beam x) the coherence of the laser beam y) the color of the laser beam z) the greater polarization of the laser beam
Last Answer : ANSWER: X -- THE COHERENCE OF THE LASER BEAM
Description : ____ is a light that can be coherent ∙ a. Spontaneous emission ∙ b. Monochromatic and in-phase ∙ c. Narrow beam divergence ∙ d. Monochromatic
Last Answer : ∙ b. Monochromatic and in-phase
Description : Under which of the following conditions does the behavior of a real gas resemble that of an ideal gas? Is it: w) under all conditions of temperature and pressure x) only at very high pressure ... when the gas is near condensation z) only at low densities when the molecules are relatively far apart
Last Answer : ANSWER: Z -- ONLY AT LOW DENSITIES WHEN THE MOLECULES ARE RELATIVELY FAR APART
Description : Planck's constant was first introduced in order to obtain a correct theoretical prediction of: w) the distribution of frequencies occurring in black body radiation. x) the energy produced by the transformation of mass into energy. y) the speed of light. z) lifetime of the neutron.
Last Answer : ANSWER: W -- THE DISTRIBUTION OF FREQUENCIES OCCURRING IN BLACK BODY RADIATION
Description : Which of the following statement(s) is/are correct? (1) Persistence is the term used to describe the duration of phosphorescence. (2) The control electrode is used to turn the electron beam on and off. (3) ... which are focussed into a narrow beam directed at the face of CRT. (4) All of the above.
Last Answer : All of the above.
Description : For an object moving in uniform circular motion, the direction of the instantaneous acceleration vector is: w) tangent to the path of motion x) equal to zero y) directed radially outward z) directed radially inward
Last Answer : ANSWER: Z -- DIRECTED RADIALLY INWARD
Description : Superconducting materials are being used in the Superconducting Super Collider to: w) cool the particles. x) minimize electrical power consumption. y) maximize the acceleration potentials. z) provide radiation shielding.
Last Answer : ANSWER: X -- MINIMIZE ELECTRICAL POWER CONSUMPTION.
Description : What does the letter "s" stand for in the acronym laser? w) scientific x) simulated y) stimulated z) solar
Last Answer : ANSWER: Y -- STIMULATED (LIGHT AMPLIFICATION BY STIMULATED MISSI)
Description : What is the wavelength of red light emitted by a helium-neon laser? w) 122 nanometers x) 633 nanometers y) 2.43 picometers z) 1.37 micrometers
Last Answer : ANSWER: X -- 633 NANOMETERS (actually 632.8 nm)
Description : A space ship traveling toward Mars at 0.6 times the speed of light c shoots an ELECTRON beam at Mars. If the electrons travel at 0.6 c RELATIVE TO THE SPACE SHIP, at what speed do the electrons impact the surface of Mars? w) 0.6 c x) 0.88 c y) 1.2 c z) 1.34 c
Last Answer : ANSWER: X -- 0.88 c
Description : When a certain beam of light falls upon a metal surface, it ejects photoelectrons from it. The number of photoelectrons ejected per second by the beam of light depends upon one of the following. Is it ... the work function of the metal y) the frequency of the beam z) the intensity of the beam
Last Answer : ANSWER: Z -- THE INTENSITY OF THE BEAM
Description : The energy associated with one photon of a light beam is proportional to one of the following. Is it proportional to: w) the intensity of the light source from which it came x) the number of photons in the beam y) the frequency of the photon z) the speed of the photon
Last Answer : ANSWER: Y -- THE FREQUENCY OF THE PHOTON
Description : A beam of white light is passed through a diffraction grating and the resulting spectrum is allowed to fall on a screen. Which one of the following is the color of light that undergoes the greatest deviation from its original direction. Is it: w) red x) yellow y) blue z) violet
Last Answer : ANSWER: W -- RED
Description : When a beam of ordinary white light is passed through a Polaroid plate filter, the intensity of the beam that emerges is: w) equal to that of the incident beam x) about 0.9 that of the incident beam y) about one-half that of the incident beam z) practically zero
Last Answer : ANSWER: Y -- ABOUT ONE-HALF THAT OF THE INCIDENT BEAM
Description : Which one gives the monochromatic emissive power for black body radiation? (A) Planck's law (B) Kirchhoff’s law (C) Wien's law (D) Stefan-Boltzmann law
Last Answer : (A) Planck's law
Description : The X –ray beam coming from an X-ray tube will be (a) Monochromatic (b) Having all wavelengths larger than a certain minimum wavelength (c) Having all wavelengths smaller than a certain maximum wavelength (d) Having all wavelengths between a minimum and a maximum wavelength
Last Answer : Ans:(b)
Description : A beam of light is incident on a large block of glass. The index of refraction of the glass is greater than one. Is the wavelength of the light in the glass: w) longer than x) shorter than y) the same as the wavelength of the light in the air?
Last Answer : ANSWER: X -- SHORTER THAN
Description : Weather satellites transmit cloud cover and temperature-humidity profiles back to Earth using images of which combination of the electromagnetic radiation types? w) infra-red and visible light x) ultraviolet and nuclear magnetic y) ultraviolet and infra-red z) ultraviolet and visible light
Last Answer : ANSWER: W -- INFRA-RED AND VISIBLE LIGHT
Description : In EXTRA-TERRESTRIAL SPACE, heat is transferred by: w) conduction x) convection y) conduction and convention z) radiation
Last Answer : ANSWER: Z -- RADIATION
Description : When radiation breaks an electron pair bond in a molecule and each fragment of the molecule gets one of the bond electrons, the molecular fragments that are formed are called: w) ions x) free radicals y) stable molecules z) gases
Last Answer : ANSWER: X -- FREE RADICALS
Description : Of the following, the most energetic form of NON-IONIZING radiation is: w) ultra-violet light x) infra-red light y) radar z) microwaves
Last Answer : ANSWER: W -- ULTRA-VIOLET LIGHT
Description : The average annual dose of NATURAL radiation by the average American is about: w) 3 millirems x) 30 millirems y) 300 millirems z) 3,000 millirems
Last Answer : ANSWER: Y -- 300 MILLIREMS
Description : Heat from the sun reaches the Earth by: w) conduction x) convection y) radiation z) none of the above
Last Answer : ANSWER: Y -- RADIATION
Description : A typical microwave oven produces microwave radiation with a wavelength of: w) 3 meters x) 3 x 10-2 meters (read: 3 times 10 to the minus 2 meters) y) 3 x 10 -6 meters (read: 3 times 10 to the minus 6 meters) z) 3 x 10-9 meters (read: 3 times 10 to the minus 9 meters)
Last Answer : ANSWER: X -- 3 x 10-2 METERS
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 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 : Heat is transferred from the sun to the earth primarily by: w) conduction x) convection y) radiation z) condensation
Description : Kinetic energy is energy of: w) position x) radiation y) motion z) formation
Last Answer : ANSWER: Y -- MOTION
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 : Laser light is very bright because it is ∙ a. Pure ∙ b. White ∙ c. Coherent ∙ d. Monochromatic
Last Answer : c. Coherent
Description : Lasers are used to produce a) Intense beam of visible light b) monochromatic beam of visible light c) coherent beam of visible light d) All of them
Last Answer : d) All of them
Description : In the Tyndall Effect, the intensity of scattered radiation is inversely proportional to the fourth power of the wavelength. Which one of the following colors of light would exhibit the most intense Tyndall scattering? w) yellow x) green y) orange z) violet
Last Answer : ANSWER: Z -- VIOLET
Description : The U.S. population receives the largest dose of ionizing radiation from: w) natural sources. x) fallout from nuclear weapons testing. y) nuclear medicine. z) nuclear power plants.
Last Answer : ANSWER: W -- NATURAL SOURCES.
Description : Monochromatic radiation of wavelength `lambda` is incident on a hydrogen sample in ground state. hydrogen atoms absorb a fraction of light and subsequ
Last Answer : Monochromatic radiation of wavelength `lambda` is incident on a hydrogen sample in ground state. ... different wavelength .Find the value of `lambda`
Description : Kirchoff’s law applies to __________ radiation. (A) Total (B) Monochromatic (C) Both (A) & (B) (D) Neither (A) nor (B)
Last Answer : (C) Both (A) & (B)
Description : Kirchoff's law is applicable to (A) Monochromatic radiation only (B) Total radiation only (C) Both (A) and (B) (D) Only volumes and not to surfaces
Last Answer : (C) Both (A) and (B)
Description : If heat transfer rate varies with the time, it is termed as (A) Forced convection (B) Steady state conduction (C) Monochromatic radiation (D) None of these
Last Answer : (D) None of these
Description : . Photo-chemical reactions occur in presence of (A) Sunlight (B) Darkness (C) Solid catalysts (D) Monochromatic radiation only
Last Answer : (A) Sunlight
Description : Photoelectric electricity is produced directly from solar energy when which of the following are absorbed in a semiconductor to create an electric current? w) protons x) electrons y) neutrons z) photons
Last Answer : ANSWER: Z -- PHOTONS
Description : In the fission of U235, what is the average number of neutrons produced in the fission reaction? w) 1.5 x) 2.5 y) 3.5 z) 4.5
Last Answer : ANSWER: X -- 2.5
Description : Magnetic fields are produced by: w) resistance x) an electric potential difference y) electric current z) stationary charge
Last Answer : ANSWER: Y -- CURRENT
Description : The magnetic field produced by a long straight wire carrying a current points: w) in the direction of the current x) toward the wire y) away from the wire z) circles around the wire
Last Answer : ANSWER: Z -- CIRCLES AROUND THE WIRE
Description : By which one of the following can a real image be produced? Can it be produced by a: w) concave mirror x) plane mirror y) diverging lens z) convex mirror
Last Answer : ANSWER: W -- CONCAVE MIRROR
Description : In the sun, helium is produced from hydrogen by: w) radioactive decay x) disintegration y) fission z) fusion
Last Answer : ANSWER: Z -- FUSION
Description : When a beam of light travels through media of two different densities, if theangle of incidence isgreater than the critical angle, _______ occurs. A) reflection B) refraction C) incidence D) criticism
Last Answer : reflection
Description : The common-emitter transistor circuit can amplify a small current signal because a small change in the signal current produces one of the following. Does the change in signal produce a large change in the: w) emitter-base voltage x) base current y) collector current z) collector voltage
Last Answer : ANSWER: Y -- COLLECTOR CURRENT
Description : The potential drop between the terminals of a battery is equal to the battery's EMF when: w) no current is drawn from the battery x) a very large current is drawn from the battery y) the internal resistance of the battery is very large z) the resistance in the external circuit is small
Last Answer : ANSWER: W -- NO CURRENT IS DRAWN FROM THE BATTERY
Description : If the average human being prefers to be directed, wishes to avoid responsibility, has relatively little ambition and wants security above all, the management attitude would be: (a) Theory Y manager ; (b) Theory X manager ; (c) Theory Z manager ; (d) All of the given options
Last Answer : (b) Theory X manager ;