In multimode step index fibre the refractive index of core and cladding is

A diffraction grating has 500 lines per mm, its grating element d is equal to:

UHS 2018
Physics
Optics, Nature of Light and Optical Instruments
Elimination Tool:

Two convex lenses of equal focal length ‘f’ are placed in contact, the resultant focal length of the
combination is

If a convex lens of focal length ‘f’ is cut into two identical halves along the lens diameter, the focal length
of each half is.

Bragg’s Law for measurement of wavelength à. of i-rays, using crystal lattice planes having distance d between each other, for constructive interference for integral multiple of i is.

NTS 2019
Physics
Optics, Nature of Light and Optical Instruments
Elimination Tool:

Michelson measured the length of a standard meter in terms of the wavelength of:

PMC Practice 2
Physics
Optics, Nature of Light and Optical Instruments
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Red light is used in photographic dark room because of:

NUMS 2020
Physics
Optics, Nature of Light and Optical Instruments
Elimination Tool:

Unit of power of a lens is

A lens, which is thicker at the center and thicker at the edges, is called.

The objective of a microscope is a lens of

Monochromatic light means the light having:

NUMS 2018
Physics
Optics, Nature of Light and Optical Instruments
Elimination Tool:

In a scanning electron microscope, image formed is:

PMC Practice 1
Physics
Optics, Nature of Light and Optical Instruments
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A line normal to the wavefront, showing the direction of the propagation of light is called the:

PMC Practice 2
Physics
Optics, Nature of Light and Optical Instruments
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An astronomical telescope has Magnifying power 5. If the focal length is 20 cm then what is the focal length of the objective?

NUMS 2019 Cancelled
Physics
Optics, Nature of Light and Optical Instruments
Elimination Tool:

What should the distance of an object from a convex lens of focal length f=10 cm in order to produce an erect image twice as large as the object?

NTS 2019
Physics
Optics, Nature of Light and Optical Instruments
Elimination Tool:

A lens which converges a beam of parallel rays to a point is called

In Double Slit experiment, the fringe spacing of the diffracted rays increases when:

UHS 2019
Physics
Optics, Nature of Light and Optical Instruments
Elimination Tool:

In a double slit experiment, two slits are 0.2 mm apart with a screen at a distance of 1m. The third bright fringe is found to be displaced at a distance of 7.5 mm from the central fringe. What is the value of the wavelength?

NUMS 2019 Cancelled
Physics
Optics, Nature of Light and Optical Instruments
Elimination Tool:

Laser beam can be used to generate three dimensional objects in a process called:

NUMS 2017
Physics
Optics, Nature of Light and Optical Instruments
Elimination Tool:

A convex and concave lens of focal length ‘f’ are in contact, the focal length of the combination will be.

Image of an object 5 mm high is only 1 cm high. Magnification produced by lens is

The power of a concave lens is

In going form a denser to rarer medium a array of light is

A double convex lens acts as a diverging lens when the object is placed

The magnifying power of a compound microscope in terms of the magnification of the objective and
magnifying power of the eyepiece is given by

Wave nature of light is proved by:

PMC Practice 1
Physics
Optics, Nature of Light and Optical Instruments
Elimination Tool:

If a single convex lens is placed close to the eye, it can be used as a

Light signals passes through multimode graded fibre due to

Lasers are used for producing an intense, ____ and coherent beam of visible light.

NUMS 2017
Physics
Optics, Nature of Light and Optical Instruments
Elimination Tool:

In Young’s double-slit experiment, if d is the separation between two slits 1 is the wavelength of light and θ is the angle of the line from the centre of slits to the point of observation on the screen; then for maxima (bright fringe); the formula is _________.

NTS 2019
Physics
Optics, Nature of Light and Optical Instruments
Elimination Tool:

There is no noticeable boundary between core and cladding.

The diameter of a lens is called

A convex lens gives a virtual image only when the objects leis

If placed in contact, the focal length of the combination of two convex lenses of equal focal lengths f,
will be

Final image produced by a compound microscope is

The minimum distance between an object and its real image in a convex lens is

The polarization of light by tourmaline crystals is due to the ______effect.

NTS 2019
Physics
Optics, Nature of Light and Optical Instruments
Elimination Tool:

Spherical aberration can be reduced by using

The interference of green photon to red photon will cause:

PMC Practice 1
Physics
Optics, Nature of Light and Optical Instruments
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Dispersional effect may produced error in light signals. This type of error is minimum in.

Dioptre power of an concave lens of 10 cm focal length is

If d is the distance of distinct vision, the magnifying power of a magnifying glass of focal length f is

A camera of 6-cm focal length is used to photograph a distant scene. The distance from the lens to the image is approximately:

NTS 2016 SMBBMC
Physics
Optics, Nature of Light and Optical Instruments
Elimination Tool:

least distance of distinct vision

Critical angle is that incident angle in denser medium for which angle of refraction is.

Magnifying power of simple microscope

If an object is placed away form ‘2f’ of a converging lens, then the image will be

The electrical signals change into light signals for transmission through optical fibre. A light pulse
represent.

A spectrometer is used to find.

The light exhibits the phenomena of constructive interference under the situation when it is ______ and ______.

NUMS 2018
Physics
Optics, Nature of Light and Optical Instruments
Elimination Tool:

for normal adjustment, length of astronomical telescope is

1. Which one type of fibre is more suitable for transmission of signals in which white light is used?Which one type of fibre is more suitable for transmission of signals in which white light is used?

If a convex lens of large aperture fails to converge the light rays incident on it to a single point, it is said to
suffer form

A point where the incident parallel rays of light converge or appear to diverge after passing through a lens
is called

In Young’s Double slit experiment, if the spacing between the slit is doubled and the linear distance from the screen is reduced to one half then the spacing between the two adjacent bright fringes will be ____ of actual value.

NUMS 2017
Physics
Optics, Nature of Light and Optical Instruments
Elimination Tool:

The least distance of distinct vision for normal eye is approximately

The least distance of distinct vision for a normal eye is

The property of light, bending around obstacles and spreading of waves into the geometrical shadow of an obstacle is called ______.

NUMS 2019 Reconduct
Physics
Optics, Nature of Light and Optical Instruments
Elimination Tool:

White light does not focus to a single point after passing through a convex lens due to

A convex lens of focal length ‘f1’and a concave lens of focal length ‘f2’ are placed in contact. The focal
length of the combination is

Chromatic aberration can be removed by using

Which of the following particles has greater wavelengths having the same velocity?

NUMS 2019 Reconduct
Physics
Optics, Nature of Light and Optical Instruments
Elimination Tool:

Coherent source of light means?

PMC Practice 3
Physics
Optics, Nature of Light and Optical Instruments
Elimination Tool:

The film of oil on water shows colour pattern when illuminated by white light due to:

NUMS 2018
Physics
Optics, Nature of Light and Optical Instruments
Elimination Tool:

In a Young’s double-slit experiment, fringes are very close to each other. How can we increase the distance between fringes?

PMC Practice 1
Physics
Optics, Nature of Light and Optical Instruments
Elimination Tool:

The property of light, bending around obstacles and spreading of waves into the geometrical shadow of an obstacle is called ______.

NUMS 2019 Reconduct
Physics
Optics, Nature of Light and Optical Instruments
Elimination Tool: