Question 1 :
The focal length of a combination of lenses formed with lenses having powers of $+2.50\ D$ and $-3.75\ D$ will be
Question 2 :
The relation among $u$, $v$ and $f$ for a mirror is:
Question 5 :
State whether the following statement is True or False. <br/>The image formed by a convex lens is real diminished and erect.
Question 6 :
A focal length of a lens is 10 cm. What is power of a lens in dioptre?
Question 8 :
State the direction of incident ray which after reflection from a spherical mirror retraces its path:
Question 9 :
Which of the following is not a characteristic of image formed by a Concave lens ?
Question 10 :
A ray of light travels from air to glass at an angle of incidence of $37^{\circ}$, the angle of refraction is $24^{\circ}$. What is the refractive index of glass?<br/>(Given: $\sin 37^{\circ} = 0.60, \sin 24^{\circ} = 0.40)$
Question 12 :
The incident ray, the _______ ray and the normal lie in the same plane during refraction.
Question 13 :
The mirror which always produces an erect and virtual image of a real object is:<br/>
Question 14 :
The focal length of a convex mirror is $20\ cm$ its radius of curvature will be
Question 15 :
What is the formula for spherical mirrors for object distance p and image distance q ?<br/>
Question 16 :
The radii of curvature of both the sides of a convex lens are $15cm$ and if the refractive index of material of the lens is $1.5$. Then focal length of lens in air is _______cm.
Question 17 :
If $f$ is the focal length of a lens, then the power of the lens is equal to
Question 19 :
The power of a lens is negative. State whether it is convex or concave?<br/>
Question 20 :
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 22 :
Ray optics fail when the size of the obstacle is :
Question 23 :
Fill in the blank. A _____ is a piece of transparent glass bounded by two spherical surfaces. 
Question 25 :
The maximum magnification that can be obtained with a convex lens of focal length $2.5\ cm$ is ( the least distance of distinct vision is $25\ cm$)
