Which of the following is an incorrect pair?

$A$ Carnot engine absorbs an amount $Q$ of heat from a reservoir at an absolute temperature $T$ and rejects heat to a sink at a temperature of $T/3$. The amount of heat rejected is

Which of the following reactions will $NOT$ occur with heated copper at $300\,^\circ C$?

If ${N_a} = \{ an : n \in N \}$,then ${N_3} \cap {N_4} = $

The energy of an electron in the $n^{th}$ orbit of a hydrogen atom is expressed as $E_n = \frac{-13.6}{n^2} \text{ eV}$. The shortest and longest wavelengths of the Lyman series are:

Water falls from a height of $60\,m$ at the rate of $15\,kg/s$ to operate a turbine. The losses due to frictional forces are $10\%$ of energy. How much power is generated by the turbine in $kW$ $(g = 10\,m/s^2)$?