[{"id":9138,"question":"For single slit diffraction the first minimum occurs when","choices":[{"text":"dsinθ =&nbsp;<span style=\"color: rgb(0, 0, 0); font-family: Georgia; font-size: 18px; line-height: 23.390625px;\">λ</span>","value":"A"},{"text":"dsinθ =&nbsp;<span style=\"color: rgb(0, 0, 0); font-family: Georgia; font-size: 18px; line-height: 23.390625px;\">λ</span>/2","value":"B"},{"text":"dsinθ = 2<span style=\"color: rgb(0, 0, 0); font-family: Georgia; font-size: 18px; line-height: 23.390625px;\">λ</span>","value":"C"},{"text":"dsinθ = m<span style=\"color: rgb(0, 0, 0); font-family: Georgia; font-size: 18px; line-height: 23.390625px;\">λ</span>","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":9137,"question":"In Young s experiment the distance between two adjacent fringes for blue light is than that for green light","choices":[{"text":"Lesser","value":"A"},{"text":"Greater","value":"B"},{"text":"Equal","value":"C"},{"text":"Lesser if distance between source and screen is large","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":9136,"question":"In electromagnetic waves electric and magnetic field ar","choices":[{"text":"Parallel","value":"A"},{"text":"Antiparallel","value":"B"},{"text":"Perpendicular","value":"C"},{"text":"Sometimes parallel sometimes perpendicular","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":9135,"question":"The ratio of fringes with for bright and dark fringes is","choices":[{"text":"1 : 2","value":"A"},{"text":"2 : 1","value":"B"},{"text":"1 : 4","value":"C"},{"text":"1 : 1","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":9134,"question":"An oil film floating on water surface show colours due to","choices":[{"text":"Interference","value":"A"},{"text":"Diffraction","value":"B"},{"text":"Scattering","value":"C"},{"text":"Reflection","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":9133,"question":"A normal to the waves front showing direction of propagating of wave is called","choices":[{"text":"Photon","value":"A"},{"text":"Particle","value":"B"},{"text":"Ray","value":"C"},{"text":"Line","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":9132,"question":"In Young s double slit experiment if we use white light then","choices":[{"text":"Colored fringes will be observed","value":"A"},{"text":"Bright fringes will be observed","value":"B"},{"text":"Alternate dark and bright fringes will be observed","value":"C"},{"text":"No interference fringes will be seen","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":9131,"question":"Which one of the following is nearly monochromatic","choices":[{"text":"Light from candle","value":"A"},{"text":"Light from simple lamp","value":"B"},{"text":"Light from sodium lamp","value":"C"},{"text":"Light from sun","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":9130,"question":"Polaroid glass is used in sun glasses because","choices":[{"text":"It is fashionable","value":"A"},{"text":"It has good color","value":"B"},{"text":"It is cheaper","value":"C"},{"text":"It reduces the light intensity to half on account of polarization","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":9129,"question":"The phenomenon of diffraction can be exhibited by","choices":[{"text":"Polarized waves only","value":"A"},{"text":"Un polarized waves only","value":"B"},{"text":"Longitudinal waves only","value":"C"},{"text":"All polarized or un polarized waves and longitudinal or transverse waves","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":9128,"question":"To observe diffraction phenomenon the size of a obstacle","choices":[{"text":"Should be much larger than the wavelength","value":"A"},{"text":"Should be of the same order as the wavelength","value":"B"},{"text":"Have no relation of wavelength","value":"C"},{"text":"Should be exactly&nbsp;<span style=\"color: rgb(0, 0, 0); font-family: Georgia; font-size: 18px; line-height: 23.390625px;\">λ/2</span>","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":9127,"question":"If Young s double slit experiment is immersed in water then the fringes with","choices":[{"text":"Decreases","value":"A"},{"text":"Remains unchanged","value":"B"},{"text":"Becomes infinite","value":"C"},{"text":"Increases","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":9126,"question":"The focal length of the lens of human eye","choices":[{"text":"Is fixed","value":"A"},{"text":"Varies from zero to infinity","value":"B"},{"text":"Can be increased only","value":"C"},{"text":"Can be decreased only","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":9125,"question":"When interference of light takes place","choices":[{"text":"Energy is created in the region of maximum intensity","value":"A"},{"text":"Energy is destroyed in region of maximum intensity","value":"B"},{"text":"Conservation of energy hold goods and energy is redistributed","value":"C"},{"text":"Conservation of energy does not hold good","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":9124,"question":"The colour of light is determined by is","choices":[{"text":"Wavelength","value":"A"},{"text":"Frequency","value":"B"},{"text":"Velocity","value":"C"},{"text":"Amplitude","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":9123,"question":"Critical angle of light passing from glass to air is minimum for","choices":[{"text":"Red","value":"A"},{"text":"Green","value":"B"},{"text":"Yellow","value":"C"},{"text":"Violet","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":9122,"question":"A completely transparent material will be invisible in vacuum when the refractive index n is","choices":[{"text":"Unity","value":"A"},{"text":"More than unity","value":"B"},{"text":"Less than unity","value":"C"},{"text":"Equal to 1.33","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":9121,"question":"Mirage is a phenomenon due to","choices":[{"text":"Reflection of light","value":"A"},{"text":"Refraction of light","value":"B"},{"text":"Total internal reflection of light","value":"C"},{"text":"Diffraction of light","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":9120,"question":"For incident angles equal or greater than the critical angle the glass air boundary will act as a","choices":[{"text":"Convex mirror","value":"A"},{"text":"Concave mirror","value":"B"},{"text":"Mirror","value":"C"},{"text":"None if them","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":9119,"question":"The danger signals are red while the eye is more sensitive to yellow because","choices":[{"text":"Scattering in yellow colour is less than that of red","value":"A"},{"text":"Red light is longer in wavelength than yellow light","value":"B"},{"text":"Scattering in red is less than that of in yellow","value":"C"},{"text":"Red colour has greater frequency than yellow light","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":9118,"question":"A driver in a lake wants to signal his distress to a person sitting on the edge of the lake flashing his water proof torch He should direct the beam","choices":[{"text":"Vertically up wards","value":"A"},{"text":"Horizontally","value":"B"},{"text":"At angle to the vertical which is slightly less than the critical angle","value":"C"},{"text":"At an angle to the vertical which is slightly more than critical angle","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":9117,"question":"Diffraction of X-ray by crystals show that","choices":[{"text":"The intensity of X-rays","value":"A"},{"text":"X-rays have very short wavelength","value":"B"},{"text":"X-rays are electromagnetic waves","value":"C"},{"text":"A-rays are just like visible light","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":9116,"question":"In Michelson interferometer if the moveable mirror is moved through a distance of&nbsp;8<span style=\"color: rgb(0, 0, 0); font-family: Georgia; font-size: 18px; line-height: 23.390625px;\">λ&nbsp;</span>then the number of fringes shifted are","choices":[{"text":"4","value":"A"},{"text":"8","value":"B"},{"text":"16","value":"C"},{"text":"32","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":9115,"question":"How many fringes will pass a reference point if the moveable mirror of a Michelson s interferometer is moved 0.06 mm The wavelength of light used is 5.89 x10<sup>-3</sup> mm","choices":[{"text":"200","value":"A"},{"text":"300","value":"B"},{"text":"20.4","value":"C"},{"text":"2.3","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":9114,"question":"Polaroids are used in","choices":[{"text":"Sun glasses","value":"A"},{"text":"The production and analysis of plane polarized light","value":"B"},{"text":"Stereoscopic motion picture","value":"C"},{"text":"All of these","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":9113,"question":"Which of the following is an optically active material","choices":[{"text":"Solution of cane sugar","value":"A"},{"text":"Liquid nitrogen","value":"B"},{"text":"Mercury","value":"C"},{"text":"Polaroid","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":9112,"question":"Wavelength of a laser beam can be used as a standard of","choices":[{"text":"Time","value":"A"},{"text":"Angle","value":"B"},{"text":"Length","value":"C"},{"text":"Temperature","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":9111,"question":"A beam of light of wavelength is incident normally on a grating of element d the angle between the zero-order and first -order spectra depends on","choices":[{"text":"<span style=\"color: rgb(0, 0, 0); font-family: Georgia; font-size: 18px; line-height: 23.390625px;\">λ&nbsp;</span>only","value":"A"},{"text":"d only","value":"B"},{"text":"<span style=\"color: rgb(0, 0, 0); font-family: Georgia; font-size: 18px; line-height: 23.390625px;\">λ&nbsp;</span>and d","value":"C"},{"text":"<span style=\"color: rgb(0, 0, 0); font-family: Georgia; font-size: 18px; line-height: 23.390625px;\">λ&nbsp;</span>d and distance of screen from the grating","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":9110,"question":"In a diffraction fringes pattern the fringes are","choices":[{"text":"Equally spaced","value":"A"},{"text":"Wider near the centre and narrower away from it","value":"B"},{"text":"Narrower near the centre and&nbsp;Wider&nbsp;away from it","value":"C"},{"text":"None of these","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":9109,"question":"Colour of thin film will not show result from","choices":[{"text":"Scattering of light","value":"A"},{"text":"Dispersion of light","value":"B"},{"text":"Interference of light","value":"C"},{"text":"Both a and b","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":9108,"question":"In Young s double slit experiment the separation between the slits in halved and the distance between the slits and the screen is doubled the fringe with will","choices":[{"text":"Be doubled","value":"A"},{"text":"Be quadrupled","value":"B"},{"text":"Remain the same","value":"C"},{"text":"Be halved","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":9107,"question":"In an interference fringes pattern the fringes are","choices":[{"text":"Equally spaced","value":"A"},{"text":"Wider near the centre and narrower away from it","value":"B"},{"text":"Narrower near the centre and wider away from it","value":"C"},{"text":"None of these","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":9106,"question":"If a point source of light is placed at the focus of a convex lens the rays coming out of the lens will constitute","choices":[{"text":"Plane wave fronts","value":"A"},{"text":"Cylindrical wave fronts","value":"B"},{"text":"Spherical wave fronts","value":"C"},{"text":"All of above","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":9105,"question":"Longitudinal waves do not exhibit","choices":[{"text":"Refraction","value":"A"},{"text":"Reflection","value":"B"},{"text":"Diffraction","value":"C"},{"text":"Polarization","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":9104,"question":"The wave nature of light was proposed by","choices":[{"text":"Einstein","value":"A"},{"text":"Maxwell","value":"B"},{"text":"Huygen","value":"C"},{"text":"Newton","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":9103,"question":"Two sources of waves are called coherent if","choices":[{"text":"Both have the same amplitude of vibrations","value":"A"},{"text":"Both produce waves of the same wavelength","value":"B"},{"text":"Both produce waves of the same wavelength having a constant phase difference","value":"C"},{"text":"Both produce waves having the same velocity","value":"D"},{"value":"E"}],"correctAnswer":3}]