The solar spectrum during a complete solar eclipse is

$A$ zone plate of focal length $60\,cm$ behaves as a convex lens. If the wavelength of incident light is $6000\,\mathring{A},$ then the radius of the first half-period zone will be:

Fraunhofer lines are produced by the absorption of light in

Two point monochromatic and coherent sources of light of wavelength $\lambda$ are placed on the dotted line in front of a large screen. The sources emit waves in phase with each other. The distance between $S_1$ and $S_2$ is $d$,while their distance from the screen is much larger. Then,
$(1) \rightarrow$ If $d = 7\lambda / 2$,$O$ will be a minima.
$(2) \rightarrow$ If $d = 4.3\lambda$,there will be a total of $8$ minima on the $y$-axis.
$(3) \rightarrow$ If $d = 7\lambda$,$O$ will be a maxima.
$(4) \rightarrow$ If $d = \lambda$,there will be only one maxima on the screen.
Which is the set of correct statements?

Evidence for the wave nature of light cannot be obtained from