The energy of the photon with a frequency of 3×10¹⁵ Hz is :

1. 1.988 × ${10}^{-18}$ J
2. 1.588 × ${10}^{-18}$ J
3. 1.288 × ${10}^{-18}$ J
4. 2.988 × ${10}^{-18}$ J

The correct arrangement of the following electromagnetic spectrum in the increasing order of frequency is:

The neon gas emits radiation of 616 nm. The number of quanta that are present in 2 J of energy is:

$1.$ $6.2$ $\times$ ${10}^{-18}$
$2.$ $5.6$ $\times$ ${10}^{17}$
$3.$ $6.2$ $\times$ ${10}^{18}$
$4.$ $32.2$ $\times$ ${10}^{-20}$
$$