Physics
The energy emitted by the Sun is due to

Chemical reaction
Nuclear fission
Nuclear fusion
All of these

ANSWER DOWNLOAD EXAMIANS APP

Physics
Light houses are places with powerful lights to :

Guide and resolve traffic jams in crowded metro-cities during nights
Indicate to the incoming warships, the location of a harbour during night
Guide and help large crowds at religious gathering during nights
Guide and warn the ships coming from different directions in the ocean

ANSWER DOWNLOAD EXAMIANS APP