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 : 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 : The number of photons emitted in 10 hours by a 60 W sodium lamp `(lambda` of photon `= 6000 Å)`
Last Answer : The number of photons emitted in 10 hours by a 60 W sodium lamp `(lambda` of photon `= 6000 Å)` A. `6. ... C. `8.40xx10^(23)` D. `3.40xx10^(23)`
Description : Consider the following statements: 1. The nuclear forces are short range forces. 2. Alpha rays emitted by a radionuclide are helium nucleus. 3. Gamma rays are electromagnetic waves. 4. Beta rays emitted by a radionuclide are negatively ... 1, 3 and 4 only (c) 1, 2, 3 and 4 (d) 1, 2 and 3 only
Last Answer : Ans:(c)
Description : Gamma rays are - (1) High energy electrons (2) Low energy electrons (3) High energy electromagnetic (4) High energy positron waves
Last Answer : (3) High energy electromagnetic Explanation: Gamma rays (γ) refer to electromagnetic radiation of an extremely high frequency and therefore consist of high energy photons.
Description : Which of the following has the highest energy? A. gamma rays (Answer) B. X-rays C. Ultra-violet radiation D. radio waves
Last Answer : A. gamma rays (Answer)
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 : X-rays region lies between – (1) Ultraviolet and visible region (2) Visible and infra-red region (3) Gamma-rays and ultraviolet region (4) Short radio waves and long radio waves
Last Answer : (3) Gamma-rays and ultraviolet region Explanation: X-rays region lies between Gamma rays and ultra-violet region.
Description : Radio waves, microwaves, infra-red spectrum, ultraviolet rays, X-rays and gamma rays are classified as ______. (1) light waves (2) electromagnetic waves (3) electric waves (4) magnetic waves
Last Answer : (2) electromagnetic waves Explanation: Electromagnetic radiation is the radiant energy released by certain electromagnetic processes. It consists of electromagnetic waves which are synchronized oscillations of electric and magnetic fields that propagate at the speed of light through a vacuum.
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 : X-rays region lies between (1) Ultraviolet and visible region (2) Visible and infra-red region (3) Gamma-rays and ultraviolet region (4) Short radio waves and long radio waves
Last Answer : Gamma-rays and ultraviolet region
Description : A hydrogen atom in state `n = 6` makes two successive transition and reaches the ground state in the first transition a photon of `1.13eV` is emitted
Last Answer : A hydrogen atom in state `n = 6` makes two successive transition and reaches the ground state in the ... is the value of n in the intermediate state?
Description : The law that states “When visible light of high frequency electromagnetic radiation illuminates a metallic surface, electrons are emitted” is known as ____________. ∙ A. Einstein law of photon ∙ B. Marconi’s law ∙ C. Maxwell’s law ∙ D. Plank’s law
Last Answer : D. Plank’s law
Description : Is the same for radio waves and gamma rays traveling in space?
Last Answer : Need answer
Description : Which of the following does NOT travel in a vacuum? A. Radio waves B. Gamma rays C. Magnetic waves D. Sound waves
Last Answer : D. Sound waves
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 : What causes photons to be emitted from excited atoms?
Last Answer : The energy difference, between two energy levels, is emitted asa photon, when the electron "falls down" to a lower energylevel.
Description : Which one of the following waves requires a material medium for their propagation? a) Light waves b) X– rays c) -rays d) Sound waves
Last Answer : d) Sound waves
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 : The ENERGY associated with a photon depends upon the photon's: w) velocity x) frequency y) amplitude z) the brightness of the source from which it comes
Last Answer : ANSWER: X -- FREQUENCY
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 beam that leaves the target is called, A. The primary X-ray B. The electrons ( from the cathode) C. The secondary rays (scattered radiation) D. X-ray photons no
Last Answer : A. The primary X-ray
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 : Pick out the wrong statement. (A) The ratio of the density of the 'nucleus' to that of the 'atom' is 10 12 (B) α-particle is identical with a doubly charged helium ion (C) The mass of deuterium atom is half that of helium atom (D) Gamma rays are high energy electrons
Last Answer : (D) Gamma rays are high energy electrons
Description : Whichofthe followingterms describesthe reason thatlightisrefractedat different angles? a. Photon energy changes with wavelength b. Light is refracted as a function of surface smoothness c. The angle is determined partly by a and b d. The angle is determined by the index of the materials
Last Answer : d. The angle is determined by the index of the materials
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 : If energy of incident photon is greater than the rest mass energy of electron positron pair, the surplus energy is shared by the pair as, a) Potential energy b) Thermal energy c) Electronic energy d) Kinetic energy
Last Answer : d) Kinetic energy
Description : The phenomena of pair production occurs only when the energy of incident photon is least equal a) 10.2 MeV b) 1.02 MeV c) 1.02 eV d) 0.102 MeV
Last Answer : b) 1.02 MeV
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 : In the annihilation of matter the number of photons produced is a) One b) Two c) Three d) None
Last Answer : b) Two
Description : An inkjet printer uses in its operation: (a) Positrons (b) Neutrons (c) An electric charge (d) Photons
Last Answer : (c) An electric charge
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 : Rest mass of the photon is a) Infinite b) Zero c) Very small d) 1.67 10-27 Kg
Last Answer : b) Zero
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 : The _____ of a detector is the fraction of incident photons that produce a photoelectron or electron-hole pair ∙ a. Responsitivity ∙ b. Photon efficiency ∙ c. Aperture ∙ d. Quantum efficiency
Last Answer : d. Quantum efficiency
Description : A beam of ultraviolet light of all wavelengths passes through hydrogen gas at room temperature, in the x. dimction. Assume thatall photons emitted due
Last Answer : A beam of ultraviolet light of all wavelengths passes through hydrogen gas at room temperature, in the ... light D. B will contain some visible light
Description : In the Compton effect, a photon of wavelength l (read: lambdw) collides with a stationary electron. The wavelength of the emitted photon is: w) longer than l x) shorter than l y) the same as l z) no photon is emitted
Last Answer : ANSWER: W -- LONGER THAN l
Description : The nature of light waves is similar to (a) Cosmic rays (b) Cathode rays (c) Alpha rays (d) Gamma rays
Last Answer : Ans:(d)
Description : Cathode rays in a discharge tube are made up of electrons emitted from the plate that is connected to the negative terminal of the DC voltage source.
Last Answer : Cathode rays in a discharge tube are made up of electrons emitted from the plate that is connected to the negative terminal of the DC voltage source.
Description : Beta rays emitted by a radioactive material are – (1) The electrons orbiting around the nucleus (2) Charged particles emitted by nucleus (3) Neutral particles (4) Electromagnetic radiations
Last Answer : (2) Charged particles emitted by nucleus Explanation: A beta ray is a high-energy, highspeed electron (negatively charged) or positron (positively charged) emitted in the radioactive decay of an atomic nucleus, such as a potassium40 nucleus, in the process of beta decay.
Description : Pick up the correct statement from the following: (A) The minimum frequency of light for which no electrons are emitted, is called threshold frequency (B) Polarising angle of glass is 57.5° (C) At the polarising angle, the reflected and refracted rays are orthogonal (D) All the above
Last Answer : Answer: Option D
Description : Beta rays emitted by a radioactive material are (1) The electrons orbiting around the nucleus (2) Charged particles emitted by nucleus (3) Neutral particles (4) Electromagnetic radiations
Last Answer : Charged particles emitted by nucleus
Description : Primary cosmic rays are composed largely of very fast-----? A. Protons (Answer) B. Neutrons C. Electrons D. Gamma rays
Last Answer : A. Protons (Answer)
Description : Biological shield in a nuclear reactor is generally provided to protect against the (A) α-rays (B) β-rays (C) Gamma rays & neutrons (D) Electrons
Last Answer : Option C
Description : Any energy which radiates in the form of radio waves, infrared waves, light waves, x-rays, etc. A. Radiant energy B. Electromagnetic C. Heat D. Ultraviolet
Last Answer : B. Electromagnetic
Description : The radiations emitted by human body lies in a) Infrared region b) Ultraviolet region c) Visible region d) None of the above
Last Answer : a) Infrared region
Description : What are transition elements? (1) Elements whose two outermost shells are incomplete (2) Elements which possess properties of both, metals and non-metals (3) They have eight electrons in the outermost shell (4) Elements whose three outermost shells are incomplete
Last Answer : (1) Elements whose two outermost shells are incomplete
Description : The noble gases have low boiling points because: w) their ionization potentials are very low x) only weak Van der Waals forces hold the atoms together y) they are produced by the fractional distillation of liquid air z) they have eight electrons in the outer shell
Last Answer : ANSWER: X -- ONLY WEAK VAN DER WAALS FORCES HOLD THE ATOMS TOGETHER
Description : Which is faster gamma waves or radio waves?
Last Answer : Both are forms of electromagnetic energy and travel at the samespeed, which is the speed of light.