Which scientist first melted two pieces of ice by rubbing them together?

A raised hammer possesses:

The width of a mirror is called the mirror?

The process of transferring of charge from a charged object to the earth is called ______________.

The separation of cream from milk by churning is due to 

Seawater can be purified by the process of -

Household appliances based on thermal effect of electric current is-

A typical example of a semiconductor is _______?