Radio Physics Past Paper PDF

## Energy of the "light particles" is related to: * Their velocity * Their frequency * Their mass * Amplitude of their oscillation ## Forces acting between particles in the nucleus are: * Only Van Der Waal forces * Only Nuclear forces * Van Der Waal forces and nuclear forces * Nuclear and electrost...

## Energy of the "light particles" is related to: * Their velocity * Their frequency * Their mass * Amplitude of their oscillation ## Forces acting between particles in the nucleus are: * Only Van Der Waal forces * Only Nuclear forces * Van Der Waal forces and nuclear forces * Nuclear and electrostatic repelling forces ## Main function of cathode in X-Ray tube is: * Emission of protons * Radiation of X-rays * Radiation of infrasound * Emission of electrons ## Which of the following has the weakest ionizing effect? * Ultraviolet radiation * X-rays * Visible light * γ-rays ## Main function of cathode in X-Ray tube is: * Emission of protons * Absorption of electrons * Emission of neutrons * Emission of electrons ## Compared to the charge and mass of a proton, an electron has: * The same charge and a smaller mass * The same charge and the same mass * An opposite charge and a smaller mass * An opposite charge and the same mass ## Which of the following is the radiation of the longest wavelength? * Ultraviolet radiation * Radio waves * Infrared radiation * X-rays ## Stability of nucleus is defined by the number of: * Protons and neutrons * Electrons * Only protons * Electrons and neutrons ## The isotopes of an element have: * Same number of neutrons * Same atomic number * Same mass number * None of these ## Strength of harmful effects of electromagnetic radiation is: * Inversely proportional to intensity of radiated energy * Not dependent on energy absorption intensity * Inversely proportional to energy absorption intensity * Proportional to energy absorption intensity ## Substantial components of eye - organ of vision -- are: * Only optical system * Receptor and optical systems * Sensor-based and optical systems * Receptor, sensor-based and optical systems ## Ultraviolet radiation is applied in medicine: * For treatment of skin diseases (psoriasis) * For treatment of ischemic diseases of the heart * Treatment of epilepsy ## Which of the following statements is false: * Ultraviolet A, B, C radiation destroy collagen fibers and cause premature aging * Ultraviolet C radiation, as highly energetic radiation, has damaging mutagenic effects, may cause direct injury (ionization) of DNA, disrupt bonds between nucleic acids, and promote the development of mutations * Ultraviolet A, B, C radiation do not destroy collagen fibers in the skin * Melanogenesis prolongs the process of sun tanning; it is revealed in 72 hours after exposure to the B ultraviolet radiation. ## Main function of cathode in X-Ray tube is: * Emission of protons * Deceleration of electrons * Maintenance of neutron number * Emission of electrons ## Which of the following statements is true: * High resistance between anode and cathode provides acceleration of electrons and direct them as a narrow beam to the anode via special devise. * High voltage between anode and cathode provides deceleration of electrons and direct them as a narrow beam to the anode via special devise. * High voltage between anode and cathode provides acceleration of electrons and direct them as a narrow beam to the anode via special devise. * High voltage between anode and cathode provides acceleration of electrons and direct them as a narrow beam to the cathode via special devise. ## Which of the following statements is true: * Major portion of kinetic energy of electrons is emitted as X-rays, the rest of is transferred to anode as thermal energy * All kinetic energy of electrons is transferred to anode as thermal energy * Kinetic energy of electrons is emitted only as x-rays. * Only a small portion (3%) of kinetic energy of electrons is emitted as X ray (97%) is transferred to anode as thermal energy. ## γ-rays (gamma rays) are electromagnetic radiation of: * The highest frequency (high energy, short wavelength) * The lowest frequency (high energy, short wavelength) * The highest frequency (low energy, short wavelength) * The highest frequency (low energy, long wavelength) ## Which of the following statements is true: * When passing through various materials x-ray photons do not interact with atoms (electrons and nuclei), hence they cannot cause ionization, generation of free electrons and low energy photons * X-rays are scattered as a result of their interaction with atoms and they do not change their direction. ## Which of the following has the weakest ionizing effect? * Ultraviolet radiation * X-rays * Visible light * γ-rays ## Metastable energy level is a level: * From which atoms spontaneously decay to the ground energy level * From which atoms cannot decay spontaneously to the ground energy level * From which atoms spontaneously transmit to the excited level * Which is characterized by short lifetime of atoms on it. ## In a helium - neon optic quantum generator laser beam is emitted by: * Helium * Uranium * Neon * Radium ## What is contributing role of helium in laser radiation in helium - neon optic quantum generator? * Provides population of 1S energy level by neon atoms * Provides population inversion between 2P and 1S energy levels of neon atoms * Provides population inversion between 3S and 1S energy levels of neon atoms * Provides population of 3S energy level by neon atoms ## Amount of specific binding energy in an atom depends on: * Size of an atom (atomic number Z) and the state of electron (energy level). * Mass number and the state of electron (energy level). * The ratio between protons and neutrons * Size of an atom (atomic number Z) and the direction of electron spin ## Effect of electromagnetic radiation depends on: * Energy and direction of spreading of photons that carry this energy * Energy and frequency (or wavelength) of photons that carry this energy ## Which of the following is the radiation of the longest wavelength? * Ultraviolet radiation * Radio waves * Infrared radiation * X-rays ## Which of the following statements is false: * Modern methods of gamma visualization are - electrocardiogrphy and electroencephalography * Gamma visualization is a method of functional diagnostics and it provides information about the intensity and the direction of metabolism in organs and tissues. * Radioactive matched atoms emit gamma photons that are fixed outside of the body * Gamma therapy is widely used in oncology to destroy cancers ## Therapeutic application (for treatment purposes) of x-rays is based on their: * Destroying effect * Restoring effect * Stimulating affect * Superficial effect ## If molecule absorbs light photon: * Electrons of outer orbital moves to the lower energy level * Electrons of outer orbital move to the higher energy level * Electrons of outer orbital do not change their state * Electrons of inner orbital leaves an atom ## Which of the following statements is false: * Transition of electron to triplet level is possible only from a excited singlet level * Part of an electron energy is dissipated as heat when electron moves from lower excited singlet level to triplet level * Fluorescence occurs only when the object is exposed to direct radiation * Since part of the energy during light energy absorption is emitted as heat, energy of quantum of luminescence is always higher than absorbed quantum energy ## Which of the following has the strongest ionizing effect? * X-rays * Ultraviolet radiation * Infrared radiation ## Stability of nucleus is defined by the number of: * Protons and neutrons * Electrons * Leptons * Electrons and quarks ## Amount of specific binding energy in an atom depends on: * Size of an atom (atomic number Z) and the state of electron (energy level). * Mass number and the state of electron (energy level). * The ratio between protons and neutrons * Size of an atom (atomic number Z) and the direction of electron spin ## When passing through various materials x-ray photons interact with atoms (electrons and nuclei), hence they can cause ionization, generation of free electrons and relatively low energy photons * X-rays do not get scattered as a result of their interaction with atoms, though they change the direction. ## Which of the following has the weakest ionizing effect * Ultraviolet radiation * X-rays * Visible light * γ-rays ## Metastable energy level is a level: * From which atoms spontaneously decay to the ground energy level * From which atoms cannot decay spontaneously to the ground energy level * From which atoms spontaneously transmit to the excited level * Which is characterized by short lifetime of atoms on it. ## In a helium - neon optic quantum generator laser beam is emitted by: * Helium * Uranium * Neon * Radium ## What is contributing role of helium in laser radiation in helium - neon optic quantum generator? * Provides population of 1S energy level by neon atoms * Provides population inversion between 2P and 1S energy levels of neon atoms * Provides population inversion between 3S and 1S energy levels of neon atoms * Provides population of 3s energy level by neon atoms ## Amount of specific binding energy in an atom depends on: * Size of an atom (atomic number Z) and the state of electron (energy level). * Mass number and the state of electron (energy level). * The ratio between protons and neutrons * Size of an atom (atomic number Z) and the direction of electron spin ## Effect of electromagnetic radiation depends on: * Energy and direction of spreading of photons that carry this energy * Energy and frequency (or wavelength) of photons that carry this energy * If electron moves near a nucleus when passing through an anode, electron is attracted by the nucleus (due to the force of electrostatic attraction) ## Which of the following is the radiation of the longest wavelength * Ultraviolet radiation * Radio waves * Infrared radiation * X-rays ## Which of the following statements is false: * Modern methods of gamma visualization are - electrocardiogrphy and electroencephalography * Gamma visualization is a method of functional diagnostics and it provides information about the intensity and the direction of metabolism in organs and tissues. * Radioactive matched atoms emit gamma photons that are fixed outside of the body * Gamma therapy is widely used in oncology to destroy cancers ## Therapeutic application (for treatment purposes) of x-rays is based on their: * Destroying effect * Restoring effect * Stimulating affect * Superficial effect ## If molecule absorbs light photon: * Electrons of outer orbital moves to the lower energy level * Electrons of outer orbital move to the higher energy level * Electrons of outer orbital do not change their state * Electrons of inner orbital leaves an atom ## Which of the following statements is false: * Transition of electron to triplet level is possible only from a excited singlet level * Part of an electron energy is dissipated as heat when electron moves from lower excited singlet level to triplet level * Fluorescence occurs only when the object is exposed to direct radiation * Since part of the energy during light energy absorption is emitted as heat, energy of quantum of luminescence is always higher than absorbed quantum energy ## Which of the following has the strongest ionizing effect? * X-rays * Ultraviolet radiation * Infrared radiation.