Question

find the heat energy supplied to the boiler containing water at 30 degree Celsius to change the temperature to 80 degree Celsius ( take specific heat of water = - 4.18 KJ/Kg k and no links

Answer 1

Dear student,
$Heatsupplied=mc∆T$
Where m is the mass of the boiler plus the mass of the water to be boiled. Your question does not have the amount of mass, so getting a specific answer is not possible.
$$\begin{gathered} Q=m\times 4.18\times (80-30) \\ Q=m\times 4.18\times 50J \end{gathered}$$

Now this depends on the mass.

Regards