The frequency of a light wave is $12 \times 10^{14} \ s^{-1}$. The wave number associated with it is .......

$A$ metal surface is exposed to solar radiation.

The energy of a radiation of wavelength $8000 \ \mathring{A}$ is $E_1$ and energy of a radiation of wavelength $16000 \ \mathring{A}$ is $E_2$. What is the relation between these two?

The photoelectric effect demonstrates:

Match the following:

List-$I$	List-$II$
$(1)$ $X$-rays	$(A)$ $\nu = 10^0 - 10^4 \ Hz$
$(2)$ Ultraviolet $(UV)$ rays	$(B)$ $\nu = 10^{10} \ Hz$
$(3)$ Long radio waves	$(C)$ $\nu = 10^{16} \ Hz$
$(4)$ Microwave	$(D)$ $\nu = 10^{18} \ Hz$

Consider two radiations of wavelengths $1. \lambda_1 = 2000 \mathring{A}$ and $2. \lambda_2 = 6000 \mathring{A}$. The ratio of the energies of these two radiations $\left(\frac{E_1}{E_2}\right)$ is . . . . . . (Nearest integer).