A screen is placed 90 cm from an object. The image an object on the screen is formed by a convex lens two different locations separated by 20 cm. Determine the focal length of the lens is
Sahay Sir > Question Answers > A screen is placed 90 cm from an object. The image an object on the screen is formed by a convex lens two different locations separated by 20 cm. Determine the focal length of the lens is
What is the shape of the wavefront in each of the following cases ? (a) Light diverging from a point source. (b) Light emerging out of a convex lens when a point source is placed at its focus. (c) The portion of the wavefront of light from a distant star intercepted by the Earth.
19
Nov
What is the shape of the wavefront in each of the following cases ? (a) Light diverging from a point source. (b) Light emerging out of a convex lens when a point source is placed at its focus. (c) The portion of the wavefront of light from a distant star intercepted by the Earth. A [...]
Fig. shows an equiconvex lens (of refractive index 1.5) in contact with a liquid layer on top of a plane mirror. A small needle with its tip on the principal axis is moved along the axis until its inverted image is found at the position of the needle. The distance of the needle from the lens is measured to be 45.0cm. The liquid is removed and the experiment is repeated. The new distance is measured to be 30.0cm. What is the refractive index of the liquid ?
19
Nov
Fig. shows an equiconvex lens (of refractive index 1.5) in contact with a liquid layer on top of a plane mirror. A small needle with its tip on the principal axis is moved along the axis until its inverted image is found at the position of the needle. The distance of the needle from the [...]
Light incident normally on a plane mirror attached to a galvanometer coil retraces backwards a shown in Fig. A current in the coil produces a deflection of 3.5^∘ in the mirror. What is the displacement of the reflected spot of light on a screen placed 1.5 m away ?
19
Nov
Light incident normally on a plane mirror attached to a galvanometer coil retraces backwards a shown in Fig. A current in the coil produces a deflection of 3.5^∘ in the mirror. What is the displacement of the reflected spot of light on a screen placed 1.5 m away ? A screen is placed 90 cm [...]
At what angle should a ray of light be incident on the face of a prism of refracting angle 60^∘ so that it just suffers total internal reflection at the other face? The refractive index of the material of the prism is 1.524.
19
Nov
At what angle should a ray of light be incident on the face of a prism of refracting angle 60^∘ so that it just suffers total internal reflection at the other face? The refractive index of the material of the prism is 1.524. A screen is placed 90 cm from an object. The image an [...]
A small telescope has an objective lens of focal length 140cm and eye piece of focal length 5.0cm. What is the magnifying power of telescope for viewing distant objects when (a) the telescope is in normal adjustment (i.e. when the image is at infinity) (b) the final image is formed at the least distance of distinct vision (25cm).
19
Nov
A small telescope has an objective lens of focal length 140cm and eye piece of focal length 5.0cm. What is the magnifying power of telescope for viewing distant objects when (a) the telescope is in normal adjustment (i.e. when the image is at infinity) (b) the final image is formed at the least distance of [...]
(i) At what distance should the lens be held from the card sheet in order to view the squares distinctly with the maximum possible magnifying power ? (ii) What is the magnification in this case ? (iii) Is the magnification equal to magnifying power in this case ? Explain.
19
Nov
(i) At what distance should the lens be held from the card sheet in order to view the squares distinctly with the maximum possible magnifying power ? (ii) What is the magnification in this case ? (iii) Is the magnification equal to magnifying power in this case ? Explain. A screen is placed 90 cm [...]
A cardsheet divided into squares each of size 1mm2 is being viewed at a distance of 9cm through a magnifying glass (a converging lens of focal length 10cm) held close to the eye. (a) What is the magnification produced by the lens ? How much is the area of each square to the virtual image ? (b) What is the angular magnification (magnifying power) of the lens ? ( c) Is the magnification in (a) equal to the magnifying power in (b) ? Explain
19
Nov
A cardsheet divided into squares each of size 1mm2 is being viewed at a distance of 9cm through a magnifying glass (a converging lens of focal length 10cm) held close to the eye. (a) What is the magnification produced by the lens ? How much is the area of each square to the virtual image [...]
For a normal eye, the far point is at infinity and the near point of distinct vision is about 25cm in front of the eye. The cornea of the provides a converging power of about 40dioptre and the least converging power of eye lens behind the cornea is about 20 dioptre. From this rough data, estimate the range of accommodation (i.e., the range of converging power of the eye lens) of a normal eye.
19
Nov
For a normal eye, the far point is at infinity and the near point of distinct vision is about 25cm in front of the eye. The cornea of the provides a converging power of about 40dioptre and the least converging power of eye lens behind the cornea is about 20 dioptre. From this rough data, [...]
You are given prism made of crown glass and flint glass with a wide variety of angles. Suggest a combination of prism which will (i) deviate a pencil of white light without much dispersion. (ii) disperse and displace a pencil of white light without much deviation.
19
Nov
You are given prism made of crown glass and flint glass with a wide variety of angles. Suggest a combination of prism which will (i) deviate a pencil of white light without much dispersion. (ii) disperse and displace a pencil of white light without much deviation. A screen is placed 90 cm from an object. [...]
A screen is placed 90 cm from an object. The image an object on the screen is formed by a convex lens two different locations separated by 20 cm. Determine the focal length of the lens is
19
Nov
A screen is placed 90 cm from an object. The image an object on the screen is formed by a convex lens two different locations separated by 20 cm. Determine the focal length of the lens is A screen is placed 90 cm from an object. The image an object on the screen is formed [...]