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

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

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:

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:

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

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:

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

A spectrometer is used to find.

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.

Magnifying power of simple microscope

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:

Final image produced by a compound microscope is

The diameter of a lens is called

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?

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:

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

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
Elimination Tool:

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

Red light is used in photographic dark room because of:

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

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:

The power of a concave lens is

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

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

Unit of power of a lens is

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:

Wave nature of light is proved by:

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

Dispersional effect may produced error in light signals. This type of error is minimum in.

The least distance of distinct vision for normal eye is approximately

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:

In a scanning electron microscope, image formed is:

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

Spherical aberration can be reduced by using

Monochromatic light means the light having:

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

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

Chromatic aberration can be removed by using

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

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

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

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:

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

least distance of distinct vision

Coherent source of light means?

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

The interference of green photon to red photon will cause:

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

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

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

The least distance of distinct vision for a normal eye is

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 objective of a microscope is a lens of

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:

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

There is no noticeable boundary between core and cladding.

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

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

Light signals passes through multimode graded fibre due to

for normal adjustment, length of astronomical telescope is

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

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

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
Elimination Tool:

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:

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

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

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 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:

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:

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