211.

Resolving power of human eye is

• 0.1"

• 1"

• 0.1'

• 1'

If distance between light source and screen is doubled, then intensity of light will become

• half

• double

• remains same

• 1/4 th

When the distance between slits of Young's double slit experiment is reduced to half then the fringe middle will become

• constant

• four times

• two times

• half

A beam of light after reflection on a plane mirror forms a real image. The beam is

• convergent

• divergent

• parallel to axis

• parallel but not to axis of mirror

In Young's double slit experiment, monochromatic light of wavelength 600 nm illuminates  the pair of slits and produces an interference pattern in which two consecutive bright fringes are separated by 10 mm. Another source of monochromatic light produces the interference pattern in which of the two consecutive bright fringes are separated by 8 mm. The wavelength of light from the second source is

• 448 nm

• 450 nm

• 480 nm

• 580 nm

Light passes through two polaroids P₁ and P₂ with pass axis of P₂ making an angle θ with the pass axis of P₁.  That value of θ for which the intensity of emergent light is zero.

• 45°

• 90°

• 30°

• 60°

If the angle between the axis of polarizer and the analyser is 45 degree, the ratio of the intensities of original light and the transmitted light after passing through the analyser is

• 2 : 1

• 1 : 2

• 2 : 3

• 1 : 1

A beam of monochromatic light is incident on one face of an equilateral prism. The angle of incidence is 55°. If the angle of emergence is 46°, then the angle of minimum deviation ${\mathrm{\delta }}_{\mathrm{m}}$will be

• > 41°

• < 41°

• = 41°

• ≥ 41°

Mark the wrong statement regarding polarisation of light

• The vibrations in a plane polarised light are perpendicular to the plane of polarisation

• If a polarised light of intensity l₀ , is passed through an analyser the intensity of light transmitted is I = l₀ cos² θ

• Polarisation is the property of longitudinal wave

• Tangent of polarising angle is equal to the refractive index of medium upon which the light is incident

The blue colour of sky is explained by

• reflection

• scattering

• polarisation

• refraction