[{"id":15548,"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 them","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":15547,"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":15546,"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":15545,"question":"One cannot see through 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 droplets in fog","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":15544,"question":"The distance between node and anti-node is","choices":[{"text":"λ","value":"A"},{"text":"λ/2","value":"B"},{"text":"λ/4","value":"C"},{"text":"2λ","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":15543,"question":"Mechanical waves on the surface 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":15542,"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":15541,"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":15540,"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":15539,"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}]