[{"id":254232,"question":"The wavelength of light observed on the earth, form a moving star is found todecrease by 0.05%. Relative to the earth the star is","choices":[{"text":"moving away with a velocity of 1.5 x 105m/s","value":"A"},{"text":"moving away with a velocity of 1.5 x 104m/s","value":"B"},{"text":"coming closer with a velocity of 1.5 x 105m/s","value":"C"},{"text":"coming closer with a velocity of 1.5 x 104m/s
","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":254230,"question":"The frequency of the fundamental mode of open at one organ pipe is 400 Hz. Ifone end of pipe is closed the fundamental frequency will be","choices":[{"text":"800 Hz","value":"A"},{"text":"600 Hz","value":"B"},{"text":"400 Hz","value":"C"},{"text":"200 Hz","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":254228,"question":"A closed organ pipe and an open organ pipe have their first overtone identical infrequency. Their lengths are in ratio","choices":[{"text":"3:4","value":"A"},{"text":"1:2","value":"B"},{"text":"2:3","value":"C"},{"text":"3:5","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":254226,"question":"When passes from medium to another, deviate from its path is called
","choices":[{"text":"reflection","value":"A"},{"text":"refraction
","value":"B"},{"text":"diffraction","value":"C"},{"text":"transmission","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":254225,"question":"A whistle is revolved with high speed in a horizontal circle of radius R. to an observer at the centre of the circle the frequency of the whistle will appear to be:","choices":[{"text":"Decreasing","value":"A"},{"text":"Increasing","value":"B"},{"text":"Both","value":"C"},{"text":"Constant","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":254223,"question":"The fundamental frequency in a stretched string is 10 Hz. To double the frequency, the tension in it must be changed to:
","choices":[{"text":"T2 = 2T1","value":"A"},{"text":"T2 = 4T1","value":"B"},{"text":"T2 = T1","value":"C"},{"text":"none of these","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":254221,"question":"The frequency of an open pipe is f. if one end is closed then its fundamental frequencywill be:
","choices":[{"text":"f/2","value":"A"},{"text":"3f/4","value":"B"},{"text":"f","value":"C"},{"text":"2f","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":254220,"question":"Where in standing wave, do the vibrations of the medium occur?","choices":[{"text":"Only at the nodes","value":"A"},{"text":"Only at the antinodes","value":"B"},{"text":"At all points between the nodes","value":"C"},{"text":"At all points between the antinodes","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":254219,"question":"A sonar depth finder in a boat uses sound signals to determine the depth of water. Fourseconds after the sound leaves the boat it returns to the boat because of reflection fromthe bottom. Assume the speed of sound in water is 1,460 meters per second. The depth of the water is, in meters, :","choices":[{"text":"2,200","value":"A"},{"text":"4,800","value":"B"},{"text":"4,400","value":"C"},{"text":"2,920","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":254218,"question":"A string vibrates in 1 loop has frequency 25 Hz if it moves in 2 loops its frequencywould be:
","choices":[{"text":"25 Hz","value":"A"},{"text":"50 Hz","value":"B"},{"text":"12.5 Hz","value":"C"},{"text":"5Hz","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":254216,"question":"A progressive sound wave is a means of transferring energy. A progressive sound waveof constant frequency is generated in air. The intensity of energy transfer is directlyproportional to another of the wave parameters. Which of the following is correct?","choices":[{"text":"Intensity πΊ (ππππππ‘π’ππ)2
","value":"A"},{"text":"Intensity πΊ (ππππππππ π‘πππ)2
","value":"B"},{"text":"Intensity πΊ (π ππππ)2
","value":"C"},{"text":"Intensity πΊ (π€ππ£ππππππ‘β)2
","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":254214,"question":"If a transverse wave has a speed of 10 m/ sec and frequency of 10 cycle/ sec itswavelength is:","choices":[{"text":"1 m","value":"A"},{"text":"10-2\r\ncm","value":"B"},{"text":"10 m","value":"C"},{"text":"10 cm","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":253009,"question":"An organ pipe open at both ends and another organ pipe, closed at one end willresonate with each \r\nother, if their lengths are in ration of","choices":[{"text":"1:1","value":"A"},{"text":"1:4","value":"B"},{"text":"2:1","value":"C"},{"text":"1:2","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":253007,"question":"The fundamental frequency of a closed organ pope is 50 Hz. The frequency ofsecond over tone is","choices":[{"text":"100hz","value":"A"},{"text":"150hz","value":"B"},{"text":"60hz","value":"C"},{"text":"250hz","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":253001,"question":"A sonometer wire 100 cm in length has a fundamental frequency of 330 Hz. Thevelocity of \r\npropagation of waves along the wire is","choices":[{"text":"115m/sec","value":"A"},{"text":"115m/sec","value":"B"},{"text":"660m/sec","value":"C"},{"text":"990m/sec","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":252998,"question":"A particular wavelength received from a galaxy is measured on earth and isfound to be 5% more\r\nthan that its wave length on earth. Hence galaxy is","choices":[{"text":"Moving towards earth","value":"A"},{"text":"Going away from earth","value":"B"},{"text":"Stationary with respect to earth","value":"C"},{"text":"None","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":252994,"question":"A stationary wave is established in a string which vibrates in four segments at afrequency of 120\r\nHz. Its fundamental frequency is:","choices":[{"text":"15Hz","value":"A"},{"text":"60Hz","value":"B"},{"text":"30Hz","value":"C"},{"text":"430Hz","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":252990,"question":"In which of the following, Dopplerβs effect is not applicable?","choices":[{"text":"To find speed of satellite","value":"A"},{"text":"To find objects under water","value":"B"},{"text":"To find speed of star","value":"C"},{"text":"To tune a musical instrument","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":252987,"question":"Bats navigate and find food by:","choices":[{"text":"Ultrasonic","value":"A"},{"text":"Echolocation","value":"B"},{"text":"Refraction","value":"C"},{"value":"D"},{"value":"E"}],"correctAnswer":2},{"id":252985,"question":"A church organ consist of open ended pipes ranging from 4m to 4 mm, if the speed ofsound is considered\r\nas 400 m/s then the min and max frequency is:","choices":[{"text":"400 Hz and 4 kHz","value":"A"},{"text":"100 Hz and 100 kHz","value":"B"},{"text":"50 Hz and 50kHz","value":"C"},{"text":"400 Hz and 400 kHz","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":252983,"question":"The spectrum of a starβs light is measured and the wavelength of one of the lines as thesodiumβs line is found \r\nto be 589 nm. The same line has the wavelength of 497 nm whenobserved in the laboratory. This means the\r\nstar is","choices":[{"text":"Moving away from the earth","value":"A"},{"text":"Moving towards the earth","value":"B"},{"text":"Stationary","value":"C"},{"text":"Revolving around the planet","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":252979,"question":"Which one is the case when the wavelength is actually changed?","choices":[{"text":"When source move relative to observer","value":"A"},{"text":"When observer move relative to source","value":"B"},{"text":"When observer moves around a stationary source at the center of circle","value":"C"},{"text":"When the relative displacement between source and observer is zero","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":252976,"question":"The maximum wavelength of a transverse wave that can be set up in a string of length Lis","choices":[{"text":"L","value":"A"},{"text":"2L","value":"B"},{"text":"V","value":"C"},{"text":"4L","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":252973,"question":"When an observer moves towards a stationary source with a speed equal to 1/5 timesof speed of sound,\r\nthe percentage increase in the frequency of sound is:","choices":[{"text":"20%","value":"A"},{"text":"40%","value":"B"},{"text":"5%","value":"C"},{"text":"10%","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":252972,"question":"In closed end organ pipe, the frequency of first harmonic is 300 Hz. The frequency ofthird overtone is :","choices":[{"text":"900 Hz","value":"A"},{"text":"1500 Hz","value":"B"},{"text":"2100 Hz","value":"C"},{"text":"600 Hz","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":252971,"question":"If source and observer are moving towards each other with same speed and aftercrossing they are\r\nreceding each other then frequency observed by observer:","choices":[{"text":"Decreases","value":"A"},{"text":"Remains constant","value":"B"},{"text":"Increases","value":"C"},{"text":"First Increases then decreases","value":"D"},{"value":"E"}],"correctAnswer":4}]