where do we use ionisation type smoke detector? and where do we use optical type smoke detectors? imean in which type of locations do we use these?
If you are talking about a lightning rod, then it is used to prevent the possibility of lightning striking your home. Since it is grounded, the air passing by it will also be at ground level to some degree. Should lightning strike then it would be shunted directly to ground through the rod and grounding cable. If you are talking about the device in electronic equipment, then there is a curcuit that appears as an open, until the voltage gains so much that it is shunted to ground and will help save the equipment. They may help with overvoltage conditions to a degree, but when you have a strike of lightning, I doubt if it will be able to shunt all the voltage quickly enough to prevent damage to the equipment, especially since they have such critical voltage devices in equipment, so you still are not safe, completely.
Get a mirror and use mirror image writing so the prof will have to use a mirror to read it. Reflective writing!
