Question 1 :
The focal length of a convex lens is $5\,cm$,where should the object be placed to get  a real image with same size as that of object:
Question 2 :
A thin film of thickness i and index of refraction 1.33 coats a glass with index of refraction 1.50. What is the least thickness/that will strongly reflect light with wavelength 600 nm incident normally?
Question 3 :
The image formed in case of a convex mirror is always ________ .
Question 4 :
The incident ray, the _______ ray and the normal lie in the same plane during refraction.
Question 5 :
A ray of light is incident perpendicularly on a glass slab. The angle of incidence is :
Question 6 :
If the light moving in a straight line bends by a small but fixed angle, it may be a case of<br>$(i)$reflection<br>$(ii)$refraction<br>$(iii)$diffraction<br>$(iv)$dispersion<br>
Question 9 :
A converging lens has a focal length of $50 cm$. The power of the lens is
Question 10 :
A spherical mirror and a thin spherical lens have each a focal length of $-15$ cm. The mirror and lens are likely to be :<br/>
Question 11 :
If the refractive index of medium $b$ with respect to medium $a$ and that of medium $c$ with respect to medium b are given, then the refractive index of a medium $c$ with respect to a medium $a$ can be found by using the relation<br/>$n_{ca}\, =\, n_{ba}\, \times\, ........$<br/><br/>
Question 12 :
If a $3cm$ tall object placed perpendicular to principal axis of a convex lens of focal length $15cm$ produces a real invented image of height $15cm$, then its object distance $(u)$ is ................ and image distance $(v)$ is ................
Question 13 :
State whether the following statement is True or False. <br/>The image formed by a convex lens is real diminished and erect.
Question 15 :
If $f$ is the focal length of a lens, then the power of the lens is equal to
Question 16 :
The power of a lens whose focal length is one metre is ______ dioptre.
Question 18 :
A convex lens is used to form real image of an object on a screen. It is observed that even when the positions of the object and that screen are fixed are two position of the lens to form real images. If the heights of the images are $4\ cm$ and $9\ cm$ respectively the height of the object is
Question 19 :
A ray of light travelling in air is incident on the plane of a transparent medium. The angle of incident is $45^0$ and that of refraction is $30^0$. The refractive index of the medium with respect to air is:
Question 20 :
The radius curvature for a convex lens is $40\ cm$, for each surface. Its refractive index is $1.5$. The local length will be
