[{"id":146063,"question":"In Young's experiment, two coherent sources are placed 0.90 mm apart and the fringes are observed one metre away. If its produces the second dark fringe at a distance of 1 mm from the central fringe, the wavelength of monochromatic light used would be","choices":[{"text":"60 x 10<sup>-4</sup>cm","value":"A"},{"text":"10 x 10<sup>-4</sup>cm","value":"B"},{"text":"10 x 10<sup>-5</sup>cm","value":"C"},{"text":"6 x 10<sup>-5</sup>cm","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":146062,"question":"If yellow light emitted by sodium lamp in Young's double slit experiment is replaced by monochromatic blue light of the same intensity","choices":[{"text":"Fringe width will decrease","value":"A"},{"text":"Fringe width will increase","value":"B"},{"text":"The fringe width will remain unchanged","value":"C"},{"text":"Fringes will becomes less intense","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":146061,"question":"Which one of the following phenomena is not explained by Hugen's construction of wavefront?","choices":[{"text":"Refraction","value":"A"},{"text":"Reflection","value":"B"},{"text":"Diffraction","value":"C"},{"text":"Origin of sepectra","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":146060,"question":"Which one of the following phenomena is not explained by Huygen's construction of wavefront?","choices":[{"text":"Refraction","value":"A"},{"text":"Reflection","value":"B"},{"text":"Diffraction","value":"C"},{"text":"Origin of spectra","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":146059,"question":"Light appears to travel in straight lines since","choices":[{"text":"It is not absorbed by the atmosphere","value":"A"},{"text":"It is reflected by the atmosphere","value":"B"},{"text":"Its wavelength is very small","value":"C"},{"text":"Its velocity is very large","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":146058,"question":"The twinkling of stars is due to","choices":[{"text":"The fact that stars do not emit light continuously","value":"A"},{"text":"The refractive index of the earth's atmosphere fluctuate","value":"B"},{"text":"Intermittent absorption of star light by its own atmosphere","value":"C"},{"text":"None of these","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":146057,"question":"A prism splits a beam of white light into its seven constituent colors. This is so because","choices":[{"text":"Phase of different colors is different","value":"A"},{"text":"Amplitude of different colors is different","value":"B"},{"text":"Energy of different colors is different","value":"C"},{"text":"Velocity of different colors is different","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":146056,"question":"A sun rise or sun set, the sun looks reddish because:","choices":[{"text":"The sun is coldest at these times","value":"A"},{"text":"Of the effects of reflection and refraction","value":"B"},{"text":"The sun is hottest at these times","value":"C"},{"text":"Of the scattering of light","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":146055,"question":"One cannot see fog because","choices":[{"text":"Fog absorbs light","value":"A"},{"text":"The refractive index of fog is infinity","value":"B"},{"text":"Light suffers total reflection at the droplet in a fog","value":"C"},{"text":"Light is scattered by the droplet in fog","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":146054,"question":"Mechanical waves on the surfaces of a liquid are","choices":[{"text":"Transverse","value":"A"},{"text":"Longitudinal","value":"B"},{"text":"Torsional","value":"C"},{"text":"both transverse and longitudinal","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":146053,"question":"Velocity of sound in a diatomic as is 300 m/sec, what is its rms velocity?","choices":[{"text":"400 m/sec","value":"A"},{"text":"40 m/sec","value":"B"},{"text":"430 m/sec","value":"C"},{"text":"300 m/sec","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":146052,"question":"At a certain instant a stationary transverse wave is found to have maximum kinetic energy. The appearance of string of that instant is:","choices":[{"text":"Sinusoidal shape with amplitude A/3","value":"A"},{"text":"Sinusoidal shape with amplitude A/2","value":"B"},{"text":"Sinusoidal shape with amplitude A","value":"C"},{"text":"Straight line","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":146051,"question":"With the propagation of a longitudinal wave through a material medium, the quantities transmitted in the propagation direction are","choices":[{"text":"Energy, momentum and mass","value":"A"},{"text":"Energy","value":"B"},{"text":"Energy and mass","value":"C"},{"text":"Energy and linear momentum","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":146050,"question":"If the amplitude of sound is doubled and the frequency reduced to one-fourth, the intensity of sound at the same point will be","choices":[{"text":"Increasing by a factor of 2","value":"A"},{"text":"Decreasing by a factor of 2","value":"B"},{"text":"Decreasing by a factor of 4","value":"C"},{"text":"Unchanged","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":146049,"question":"For production of beats the two sources must have","choices":[{"text":"Different frequencies and same amplitude","value":"A"},{"text":"Different frequencies","value":"B"},{"text":"Different frequencies, same amplitude and same phase","value":"C"},{"text":"Different frequencies and same phase","value":"D"},{"value":"E"}],"correctAnswer":2}]