SONAR is a device that is used to measure the distance of underwater objects by a ship. Which of the following types of waves does it use for this purpose?
Infrasonic waves
Sound waves in audible range for human beings
Ultrasonic waves
All of the above
For election to the Lok Sabha, a nomination paper can be filed by
Miscellaneous · Easy
In a month if the seventh day is three days earlier than Saturday,then the nineteenth day of the month will be a
Miscellaneous · Easy
Which among the following events happened earliest ?
Miscellaneous · Easy
An 80-litre solution of alcohol and water has 75% alcohol. How much water (in litres) must be added to bring down the concentration of alcohol to 60%?
Miscellaneous · Easy