13 sec
3 sec
1 sec
5 sec
To convert Ac to DC
To convert temperature from Celcius to Kelvin scale, you must _ the given temperature.
To hear a clear echo, the minimum distance should be
To increase the magnifying power of telescope, we should increase
To measure the speed of an approaching car a police officer shines
To open a door easily, the handle should be fixed
To prevent damage from lightning, lightning conductors are used on tall structures. The lightning conductor
To produce deflection in a television picture tube
To produce sound it is necessary that
Total internal reflection can not take place when light goes from :
