Question 2 :
Light moves from air into water. The light makes an angle of $47^0$ with the normal in the air. What angle will it make with the normal in the water?<br/>The index of refraction for air is $1.00$.<br/>The index of refraction for water is $1.33$.
Question 3 :
Focal length of a lens is 50 cm. Its power would be :
Question 4 :
Magnification is 0.5 when the object distance is 10 cm. Find the power of the concave lens :
Question 5 :
A concave lens forms the image of an object which is :<br><br>
Question 6 :
A virtual image larger than the object can be produced by a
Question 7 :
No matter where the object is placed in front of a mirror, the image formed is virtual, erect and smaller than the object. This mirror must be:
Question 8 :
A ray of light is incident perpendicularly on a glass slab. The angle of incidence is :
Question 10 :
The constant ratio of the sine of angle of incidence to the sine of angle of refraction is also known as:
Question 12 :
The focal length of convex lens is 30 cm and the size of image is quarter of the object, then the object distance is:-
Question 14 :
State whether true or false.<br/>The images formed by a convex mirror are always erect and enlarged.
Question 15 :
What is the nature of image formed by Concave lens ?
Question 16 :
The power of a convex lens of focal length $2$ metre will be:
Question 18 :
A ray of light travelling in air strikes the surface of glass at angle of $45^{\circ}$. The angle of refraction in the glass will be :
Question 19 :
An object of height $1.5\ cm$ is placed on the axis of a convex lens of focal length $25\ cm$. A real image is formed at a distance of $75\ cm$ from the lens. The size of the image will be
Question 20 :
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 21 :
The power of a lens having a focal length of $1\;cm$ is :
Question 23 :
In case of a real and inverted image, the magnification created by the mirror is<br/>
Question 24 :
During refraction through a glass block, the angle of refraction _______.
Question 25 :
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 27 :
A wave has velocity v in medium P and velocity 2v in medium Q. If the wave is incident in medium P at an angle of 30, then the angle of refraction will be
Question 28 :
If the focal length of a lens is $50\;cm$, its power would be
Question 29 :
If $f$ is the focal length of a lens, then the power of the lens is equal to
Question 30 :
In case of a virtual and erect image, the magnification created by the mirror is
Question 31 :
When a ray of light passes from an optically less dense medium to a more dense medium, it :
Question 32 :
A ray of light passing through the .......... of the lens, passes on undeviated.
Question 34 :
Fill in the blanks:Principal axis is also called ________ of the lens.
Question 35 :
When a drop of oil is spread on a water surface, it displays beautiful colours in daylight because of :
Question 36 :
When the object is at focus of a concave mirror, the image is formed at
Question 37 :
Choose the correct answer:<br>The nature of image formed by convex mirror is:
Question 38 :
A ray of light incident at a point on the principal axis of a convex lens passes undeviated through the lens. What special name is given to this point on the principal axis?<br>
Question 39 :
The focal length of a concave lens is $2m$. Then the power of the lens is:<br/>
Question 40 :
Under which of the following conditions will a convex mirror of focal length <i>f</i> produces an image ofreal object that is erect, diminished and virtual
Question 41 :
What is the power of the lens, if the far point of a short sighted eye is $200\ cm$?
Question 42 :
What is the power of a concave lens of focal length50 cm?
Question 43 :
Ratio of the size of the image to the size of the object is known as:
Question 45 :
A convex mirror of focal length $f$ forms an image which is $\dfrac{1}{n}$ times the object. The distance of the object from the mirror is:
Question 46 :
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 47 :
For an object at infinity, a concave mirror produces an image at its focus which is :
Question 48 :
Height of the image of an object on an principal axis produced by a convex lens is double the focal length of lens is $20 cm$, then image distance from the lens is:
Question 49 :
The relation between the linear magnification $m,$ the object distance $u$ and the focal length $f$ is
Question 50 :
How does the power of a lens change if its focal length is doubled?<br>
