Optics Answers

The potential difference across the terminals of a battery with an internal resistance of 0.5 Ohms in a closed and open circuit are 8.5 V and 12.0V, respectively. How much current is flowing when the circuit is closed?

A manufacturer wishes to fabricate a step index optical fibre from a material such that relative core-cladding index difference is 0.01. The refractive index of cladding is 1.3. In other case, keeping the material of the core same, the cladding material is replaced by another medium, such that core-cladding index difference is now 0.02. Calculate the ratio of light gathering ability of the optical fibre for the two cases with refractive index of outer medium to be 1. Compare the two cables for their applications in communication. Suggest the measures to be done if graded index fibre is to be fabricated in both the cases and how it is going to change the properties and applications of cable.

A person is lying on a diving board 3.00 m above the surface of the water in a swimming pool. She looks at a penny that is on the bottom of the pool directly below her. To her, the penny appears to be a distance of 7.00 m from her. What is the depth of the water at this point?

    A person is lying on a diving board 3.00 m above the surface of the water in a swimming pool. She looks at a penny that is on the bottom of the pool directly below her. To her, the penny appears to be a distance of 7.00 m from her. What is the depth of the water at this point?

  A lens forms an image of an object. The object is 16.0 cm from the lens. The image is 12.0 cm from the lens on the same side as the object. (a) What is the focal length of the lens? Is the lens converging or diverging? (b) If the object is 8.50 mm tall, how tall is the image? Is it erect or inverted? (c) Draw a principal-ray diagram.

A pencil that is 9.0 cm long is held perpendicular to the surface of a plane mirror with the tip of the pencil lead 12.0 cm from the mirror surface and the end of the eraser 21.0 cm from the mirror surface. What is the length of the image of the pencil that is formed by the mirror? Which end of the image is closer to the mirror surface: the tip of the lead or the end of the eraser?

When an object is placed 6cm from the objective lense of a compound microscope the final image is two-third from the object and it is at the LDDV, calculate the focal length of the two lenses assuming that the magnification power of the instrument is 14. calculate also the separation of the two lenses

Mirage. The figure below shows a simplified situation of a mirage. The air is

stratified into three layers with refractive indices ni with i = 1, 2, 3. The continuous

variation of refractive index with height on a hot day is similar for n3 > n2 > n1.

The bottom two layers have a thickness of a and b, respectively. An observer

at height h is looking at a tree of height H. Calculate the minimum horizontal

distance between the tree and the observer so that the observer sees a mirage. Take

n3 = 1.01, n2 = 1.02, n3 = 1.03, a = b = 0.5 m, h = 2 m, and H = 10 m.

A Young’s-double-slit experiment is performed with two wavelengths - 400 and 800

nm. Assume that both sources are perfectly coherent with each other and have

equal intensity. Calculate the light-intensity pattern on a screen placed 1 m from

the slits, which are separated by a distance of 1 cm.

Two plane waves of light with wavelength 500 nm are incident on a screen. If the

spatial resolution of the detector is 0.1 mm, what is the maximum angle between

the two waves for which we can resolve the fringes. Assume we can resolve fringes if

the distance between the maxima and minima is equal to the detector resolution.