# A level Wave Optics Quiz 1

#### Quiz Description

A level Wave Optics Quiz. In physics, physical optics, or wave optics, is the branch of optics that studies interference, diffraction, polarization, and other phenomena for which the ray approximation of geometric optics is not valid. This usage tends not to include effects such as quantum noise in optical communication, which is studied in the sub-branch of coherence theory.

Physical optics is also the name of an approximation commonly used in optics, electrical engineering and applied physics. In this context, it is an intermediate method between geometric optics, which ignores wave effects, and full wave electromagnetism, which is a precise theory. The word "physical" means that it is more physical than geometric or ray optics and not that it is an exact physical theory. :11–13

This approximation consists of using ray optics to estimate the field on a surface and then integrating that field over the surface to calculate the transmitted or scattered field. This resembles the Born approximation, in that the details of the problem are treated as a perturbation.

In optics, it is a standard way of estimating diffraction effects. In radio, this approximation is used to estimate some effects that resemble optical effects. It models several interference, diffraction and polarization effects but not the dependence of diffraction on polarization. Since this is a high-frequency approximation, it is often more accurate in optics than for radio.

In optics, it typically consists of integrating ray-estimated field over a lens, mirror or aperture to calculate the transmitted or scattered field.

In radar scattering it usually means taking the current that would be found on a tangent plane of similar material as the current at each point on the front, i. e. the geometrically illuminated part, of a scatterer. Current on the shadowed parts is taken as zero. The approximate scattered field is then obtained by an integral over these approximate currents. This is useful for bodies with large smooth convex shapes and for lossy (low-reflection) surfaces.

Polarisation of light proves

Correct
• corpuscular nature of light.
• quantum nature of light.
• transverse wave nature of light.
• longitudinal wave nature of light.

The wavefront due to a source situated at infinity is

Correct
• spherical
• cylindrical
• planar
• circular

A laser beam is coherent because it contains

Correct
• waves of several wavelengths.
• incoherent waves of a single wavelength.
• coherent waves of several wavelengths
• coherent waves of a single wavelength.

According to Huygens’ principle, light is a form of

Correct
• particle
• rays
• wave

Two coherent monochromatic light beams of intensities I and 41 superimpose. The maximum and minimum possible intensities in the resulting beam are:

Correct
• 5I and I
• 5I and 3I
• 3I and I
• 9I and I

What is path difference for destructive interference?

Correct
• n(λ +1)
• (2n + 1)λ/2
• (n +1)λ/2

When exposed to sunlight, thin films of oil on water of ten exhibit brilliant colours due to the phenomenon of

Correct
• interference
• diffraction
• dispersion
• polarisation

What happens, if the monochromatic light used in Young’s double slit experiment is replaced by white light?

Correct
• No fringes are observed.
• All bright fringes become while.
• All bright fringes have colour between violet and red.
• Only the central fringe is white and all other fringes are coloured.

When compact disk is illuminated by a source of white light, coloured lines are observed. This is due to

Correct
• dispersion
• diffraction
• interference
• refraction

When unpolarised light beam is incident from air onto glass (n = 1.5) at the polarising angle.

Correct
• Reflected beam is polarised completely
• Reflected and refracted beams are partially polarised
• Refracted beam is plane polarised
• Whole beam of light is refracted

Resolving power of microscope depends upon

Correct
• wavelength of light used (directly proportional)
• wavelength of light used (inversely proportional)
• frequency of light used
• focal length of objective

The phenomenon of interference is based on

Correct
• conservation of momentum.
• conservation of energy.
• conservation of momentum and energy.
• quantum nature of light.

A double slit interference experiment is carried out in air and the entire arrangement is dipped in water. The fringe width

Correct
• increases
• decreases
• remains unchanged.
• fringe pattern disappears.

In Young’s double slit experiment, if the monochromatic source of yellow light is replaced by red light, the fringe width

Correct
• increases
• decreases.
• remains unchanged.
• the fringes disappear

The angle of incidence at which reflected light is totally polarised for reflection from air to glass (refractive index n) is

Correct
• arcsin(n)
• arcsin(1/n)
• arctan(1/n)
• arctan(n)

A laser beam is used for locating distant objects because

Correct
• it is monochromatic
• it is not chromatic
• it is not observed
• it has small angular spread.