Practice Test

Q1) The electromagnetic waves are : Show Answer

Q2) The electromagnetic waves are produced by : Show Answer

Q3) The electromagnetic waves may be produced by : Show Answer

Q4) The direction of propagation of electromagnetic waves is along : Show Answer

Q5) The electromagnetic waves in free space travel with : Show Answer

Q6) The speed c of electromagnetic waves through vacuum is given by : Show Answer

Q7) The ratio of electric field vector (E) to magnetic field vector (B) i.e., E/B has the dimensions of : Show Answer

Q8) The wave impedance of free space is : Show Answer

Q9) A wave is propagating in a medium of dielectric constant (i.e. relative permittivity ) 2 and relative permeability 50. The wave impedance of such a medium is : Show Answer

Q10) An electromagnetic wave is travelling along Z-axis. Which of the following pairs of space and time varying electric and magnetic fields would generate such a wave : Show Answer

Q11) In an electromagnetic wave : Show Answer

Q12) A circuit contains inductance Land capacitance C. The frequency of electromagnetic waves produced is : Show Answer

Q13) The electromagnetic theory of light was developed by: Show Answer

Q14) The idea of displacement was given by : Show Answer

Q15) The S.I. unit of displacement current is : Show Answer

Q16) The displacement current arises due to : Show Answer

Q17) The scientist who first produced and observed the electromagnetic waves was : Show Answer

Q18) The transmission of electromagnetic waves was first demonstrated by : Show Answer

Q19) Waves used for telecommunication are : Show Answer

Q20) The name of the first Indian Scientist who experimentally confirmed the existence of electromagnetic waves is: Show Answer

Q21) The range of microwaves is : Show Answer

Q22) The waves used in Radar are : Show Answer

Q23) To double the covering range of a T.V. transmitting tower, its height should be increased to : Show Answer

Q24) Which of the following has shortest wavelength : Show Answer

Q25) Which of the following has largest wavelength : Show Answer

Q26) Which one of the following forms the part of electromagnetic spectrum : Show Answer

Q27) The wavelength 10 mm corresponds to : Show Answer

Q28) The electromagnetic radiation are in descending order of wave length in the following sequence: Show Answer

Q29) A man can take pictures of those objects which are not fully visible to the eye using camera films acceptable to : Show Answer

Q30) Which of the following wavelengths represents blue light ? Show Answer

Q31) Which of the following wavelengths represents red light ? Show Answer

Q32) Radiowaves and visible lights have : Show Answer

Q33) The Ozone layer of atmosphere absorbs : Show Answer

Q34) 'Green house effect' is due to : Show Answer

Q35) In the absence of atmosphere around the earth, the average surface temperature of earth : Show Answer

Q36) The wavelength 21 cm emitted by atomic hydrogen in intersteller space belongs to : Show Answer

Q37) The frequency 1057 MHZ of radiation arising from two close energy levels in hydrogen belongs to : Show Answer

Q38) The wave associated with 2.7 Kelvin belongs to : Show Answer

Q39) The frequency modulated waves are : Show Answer

Q40) The amplitude modulated waves are : Show Answer

Q41) A T.V. tower has a height h metre. If the radius of earth R metre, the area covered by the T.V> broadcast is ( if h < < R) Show Answer

Q42) The energy of electromagnetic waves is due to their : Show Answer

Q43) To which region of electromagnetic spectrum the frequency, 1 BHz correspond ? Show Answer

Q44) The frequency of radiowaves corresponding to a wavelength 10 m is : Show Answer

Q45) A magnetic field can be produced by : Show Answer

Q46) To obtain the X-ray photograph of hand, we use the principle of : Show Answer

Q47) The structure of solids is investigated by using : Show Answer

Q48) Beyond which frequency, the ionosphere bends any incident electromagnetic radiation but does not reflect it back towards the earth ? Show Answer

Q49) Radiowaves do not penetrate in the band of : Show Answer

Q50) A radar sends the waves towards a distant object and receives the signal reflected by object. These waves are : Show Answer

Q51) The frequency of visible light is of the order of : Show Answer

Q52) The wave-length of X-rays is of the order of: Show Answer

Q53) X-rays are produced by jumping of : Show Answer

Q54) The wavelength of X-rays lies between : Show Answer

Q55) The penetrating power of X-rays increases with the increase in its : Show Answer

Q56) The production of X-rays is a phenomenon for the conservation of : Show Answer

Q57) The shortest wavelength of X-rays emitted from X-ray tube depends upon : Show Answer

Q58) The voltage applied across an X-rays tube is nearly equal to : Show Answer

Q59) X-rays are not used for radar purposes, because they are not : Show Answer

Q60) The wavelength of ultraviolet rays is of the order of: Show Answer

Q61) The wavelength of infrared rays is of the order of: Show Answer

Q62) The energy of X-ray photon is 2200 eV. Its frequency would be: Show Answer

Q63) A gold leaf electroscope is charged and the leaves are observed to diverge by a certain amount. A beam of X-rays is allowed to fall upon the electroscope for a short period. The leaves would: Show Answer

Q64) A laser beam is sent to the moon and reflected back to earth by a mirror placed on the moon by an astronaut. If the moon is 384000 km from earth, how long does it take the light to make the round trip ? Show Answer

Q65) The proton energy in units of eV for electromagnetic waves of wavelength 2 cm is Show Answer

Q66) The correct sequence of the increasing wavelength of the given radiation sources is: Show Answer

Q67) The density of air at the top of stratosphere in comparison to that of near of the earth's surface is: Show Answer

Q68) The density of air at the top of mesosphere in comparison to that of near of the earth's surface is: Show Answer

Q69) The atmosphere above the height of 80 km is called : Show Answer

Q70) Ozone layer blocks the radiations of wave: Show Answer

Q71) Television signals reach us only through the ground waves. The range R related with the transmitter height h is proportion to: Show Answer

Q72) If the earth did not have atmosphere, its surface temperature on a day time would be: Show Answer

Q73) Height 'h' of transmitting antenna when R is radius of earth to have range 'd' is : Show Answer

Q74) If there were no atmosphere, the average temperature on the surface of the earth would be: Show Answer

Q75) The velocity of light in vaccum can be changed by changing : Show Answer

Q76) When light travels from air to water, which parameter does not change ? Show Answer

Q77) The difference between soft and hard X-rays is of: Show Answer

Q78) What is cause of "Green house effect" ? Show Answer

Q79) The velocity of electromagnetic wave is parallel to : Show Answer

Q80) Which of the following e.m. waves has highest wave length ? Show Answer

Q81) Which of the following rays are not electromagnetic waves ? Show Answer

Q82) The maximum distance up to which TV transmission from a TV tower of height h can be received is proportional to : Show Answer

Q83) Velocity of light is maximum in Show Answer

Q84) According to Maxwell hypothesis, a changing electric field gives rise to : Show Answer

Q85) Which scientist experimentally proved the existence of e.m. waves ? Show Answer

Q86) Radio frequency choke uses core of Show Answer

Q87) Sodium lamps are used in foggy -conditions because : Show Answer

Q88) The pressure exerted by e.m wave of intensity I on a non-reflecting surface is ( where c = velocity of light ) : Show Answer

Q89) Due to Earth's magnetic field, charged cosmic rays particles Show Answer

Q90) Particles having positive charges occasionally come with high velocity from sky towards earth, they will be deflected towards the Show Answer

Q91) If there were no atmosphere, earth would have been Show Answer

Q92) The effectiveness of glass houses to keep plants warm is due to Show Answer

Q93) Which of the following waves has maximum intensity ( Wavelength, Frequency ) Show Answer

Q94) Which one is one electromagnetic in nature Show Answer

Q95) Electromagnetic radiation of highest frequency is : Show Answer

Q96) The electric and magnetic field of an electromagnetic wave are : Show Answer

Q97) Displacement current is same as : Show Answer

Q98) Which of the following waves are relevant to telecommunication : Show Answer

Q99) In vacuum the speed of electromagnetic waves depends upon : Show Answer

Q100) The law which states that the variation of electric field causes magnetic field is : Show Answer

Q101) If R is the radius of earth and h is height of T.V. transmitting tower, then the covering range of transmitter will be : Show Answer

Q102) The relation between electric field E and magnetic field H in an electromagnetic wave is : Show Answer

Q103) The relation between electric field E and magnetic field induction B in electromagnetic waves : Show Answer

Q104) The energy of electromagnetic wave in vacuum is given by the relation : Show Answer

Q105) An electromagnetic wave is propagating along Y-axis. Then : Show Answer