[{"id":170219,"question":"Old people cannot hear sound above than:
","choices":[{"text":"1000 Hz
","value":"A"},{"text":"15000 Hz
","value":"B"},{"text":"20000 Hz
","value":"C"},{"value":"D"},{"value":"E"}],"correctAnswer":2},{"id":170217,"question":"To hear echoes, the minimum distance of the obstacle from source of sound should be:","choices":[{"text":"10m","value":"A"},{"text":"15m","value":"B"},{"text":"17m","value":"C"},{"text":"20m","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":170216,"question":"The sound level of rustling of leave is:
","choices":[{"text":"1 dB
","value":"A"},{"text":"20 dB
","value":"B"},{"text":"30 dB
","value":"C"},{"text":"10 dB
","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":170215,"question":"The frequency of silent whistle is:
","choices":[{"text":"20,000 Hz – 25000Hz
","value":"A"},{"text":"2000 Hz – 2500Hz
","value":"B"},{"text":"200 KHz – 2000 Hz
","value":"C"},{"text":"25000 KHz
","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":170214,"question":"The speed of sound in iron at 25°C is:
","choices":[{"text":"5950 m/sec
","value":"A"},{"text":"5900 m/sec
","value":"B"},{"text":"6950 m/sec
","value":"C"},{"text":"6940 m/sec
","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":170212,"question":"The speed of sound in are water at 25°C is:","choices":[{"text":"1530ms-1","value":"A"},{"text":"1531ms-1","value":"B"},{"text":"1560ms-1","value":"C"},{"text":"1570ms-1","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":170211,"question":"The speed of sound in air at 0°C is:
","choices":[{"text":"331ms-1
","value":"A"},{"text":"376ms-1
","value":"B"},{"text":"231ms-1
","value":"C"},{"text":"386ms-1
","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":170209,"question":"Frequency of tuning fork depends upon its …………. of prongs:
","choices":[{"text":"Weight","value":"A"},{"text":"Speed","value":"B"},{"text":"Mass","value":"C"},{"text":"Distance","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":170208,"question":"The intensity of lawn mover is:
","choices":[{"text":"10-1 wm-2
","value":"A"},{"text":"10-2 wm-2
","value":"B"},{"text":"10-3 wm-2
","value":"C"},{"text":"10-4 wm-2
","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":170207,"question":"The unit of intensity of sound:
","choices":[{"text":"Wm-1
","value":"A"},{"text":"Wm-2
","value":"B"},{"text":"Wm
","value":"C"},{"text":"Wm2
","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":170205,"question":"Bats can hear sound of frequency up to:
","choices":[{"text":"100,000Hz
","value":"A"},{"text":"25000Hz
","value":"B"},{"text":"120, 000Hz
","value":"C"},{"text":"1000Hz
","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":170204,"question":"The speed of sound in air at 21 °C is:
","choices":[{"text":"336ms-1
","value":"A"},{"text":"343ms-1
","value":"B"},{"text":"430ms-1
","value":"C"},{"text":"470ms-1
","value":"D"},{"value":"E"}],"correctAnswer":2}]