Questions in Ray Optics and Optical Instruments

Select	Question
	In the formation of primary rainbow, the sunlight rays emerge at minimum deviation from rain-drop after
	Dispersive power depends upon
	When white light passes through the achromatic combination of prisms, then what is observed
	The dispersion for a medium of wavelength $\lambda$ is $D$, then the dispersion for the wavelength $2 \lambda$ will be
	The refractive index of a prism for a monochromatic wave is $\sqrt{2}$ and its refracting angle is 60°. For minimum deviation, the angle of incidence will be
	The ratio of angle of minimum deviation of a prism in air and when dipped in water will be ($_{a}{{\mu }_{g}}=3/2$ and $_{a}{{\mu }_{w}}=4/3$)
	The respective angles of the flint and crown glass prisms are $A’$ and $A$. They are to be used for dispersion without deviation, then the ratio of their angles $A’ /A$ will be
	The number of wavelengths in the visible spectrum
	The black lines in the solar spectrum during solar eclipse can be explained by
	The dispersive power is maximum for the material