Which one of the following statements is not correct ?
Ultrasonic waves cannot get reflected, refracted or absorbed.
Ultrasonic waves are used to detect the presence of defects like cracks, porosity, etc. in the internal structure of common structure materials.
Ultrasonic waves can be used for making holes in very hard materials like diamond.
Ultrasonic waves cannot travel through vacuum.
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