Question

What will happen if fossil fuels like coal and petroleum are completely exhausted?

Answer 1

Well today India is mostly dependent on fossil fuels for energy and if the fossil fuels get exhausted it will be very dangerous  problem.
The production will energy will decrease to large extent and even the effectiveness in work and its quality will decrease to large extent .
The equipments working on electricity will energy shortage 
And due to energy shortage there will be continuous load shedding and thus the will be disturbances in doing work .
Even the business companies depending on electricity would face many problems in handling the companies needs and even may result in it collapse 
The time required for completion work will be more because of no energy supply and even there are many reasons due which the overall progress of country will reduce
Hope this helped you
:-)

Answer 2

Coal and petroleum are the natural resources which are important resources of energy for us

Coal is used as fuel as such in homes and in industry,it is used to generate electricity at thermal power plants

Petroleum products such as petrol & diesel are used as fuels in transport to run scooters cars busses motorcycles trains &aeroplanes

Kerosene & LPG obtained from petroleum are used as domestic fuels for cooking food

Since the industrial revolution we have been using increasing amount of energy

So without coal and petroleum products life on earth is impossible