(I) Light is basic need of physiological processes of plants.
(II) The visible part of light is made-up of wavelength from about 500 nm (violet) to 600 nm (red).
(III) The rate of photosynthesis is maximum at blue (400 - 500 nm) and green 600 nm.
(IV) The green (500 - 600 nm) wave length of spectrum is less strongly absorbed by plants.

Light of wavelength 500 nm Pass through a slit of 0.2 mm wide. The diffraction pattern is formed on a screen 60 cm away. Determine the. (i) angular spread of centeral maximum (ii) the distance between the central maximum and the second minimum. =

Two slits are made 1 min apart and the screen is placed 1 m away from the slits. What is the firnge separation when blue green light of wavelength 500 nm is used?

In Young's double slit experiment, the distance of the screen from the two slits in 1m. When a light of wavelength 600nm is allowed to fall on the slits width of the fringes obtained on the screen is 2mm. Calculate the width of the fringe if the wavelength of the incident light is 400nm. Calculate band width in each case if the arrangement is immersed in water of refractive index 1.33.

The wavelength of light in the visible region is about 390 nm for violet colour, about 550 nm (average wavelength) for yellowgreen colour and about 760 nm for red colour. (a) What are the energies of photons in (eV) at the (i) violet end, (ii) average wavelength, yellow-green colour, and (iii) red end of the visible spectrum? ("Take h "= 6.63xx10^(-34)" J s and 1 eV" = 1.6xx10^(-19)J.) (b) From which of the photosensitive materials with work functions listed in Table 11.1 and using the results of (i), (ii) and (iii) of (a), can you build a photoelectric device that operates with visible light?

In a Young's double slit experiment, the separation between the slits = 2.0 mm, the wavelength of the light = 600 nm and the distance of the screen from the slits = 2.0 m. If the intensity at the centre of the central maximum is 0.20 W m^-2 , what will be the intensity at a point 0.5 cm away from this centre along the width of the fringes ?

Two groups (A & B) of bean plants 450nm & Group B to light of wave of similar size and same leaf area were length of 500-550nm. Compare the placed in identical conditions. Group A photosynthetic rate of the2 groups givwas exposed to light of wavelength 400 reasons.

Find the angular separation between the consecutive bright fringes in a Young's double slit experiment with blue-green light of wavelength 500 nm. The separation between the slits is 2.0 x 10^ -3 m.

A source emitting light of wavelengths 480 nm and 600 nm is used in a double slit interference experiment. The separation between the slits is 0.25 mm and the interference is observed on a screen placed at 150 cm from the slits. Find the linear separation between the first maximum (next to the central maximum) corresponding to the two wavelengths.