If the mean wavelength of light radiated by a $100 \ W$ lamp is $5000 \ \mathring{A}$,then the number of photons radiated per second is:

An ultraviolet bulb emits light of wavelength $400 \ nm$ and an infrared bulb emits light of wavelength $700 \ nm$. If both are rated at $130 \ W$,what is the ratio of the number of photons emitted per second by the $UV$ and $IR$ sources?

Find the number of photons emitted per second by a $100 \ W$ bulb emitting light of wavelength $540 \ nm$. (Given: $h = 6 \times 10^{-34} \ J \cdot s$)

The energy of a quantum of frequency $10^{15} \ Hz$ and $h = 6.6 \times 10^{-34} \ J \cdot s$ will be:

$A$ perfectly reflecting mirror of mass $M$ mounted on a spring constitutes a spring-mass system of angular frequency $\Omega$ such that $\frac{4 \pi M \Omega}{h} = 10^{24} \text{ m}^{-2}$,where $h$ is Planck's constant. $N$ photons of wavelength $\lambda = 8 \pi \times 10^{-6} \text{ m}$ strike the mirror simultaneously at normal incidence such that the mirror gets displaced by $1 \mu\text{m}$. If the value of $N$ is $x \times 10^{12}$,then the value of $x$ is. . . . . . . . [Consider the spring as massless]

Which of the following phenomena cannot be explained by the wave theory of light?