Question 1 :
The sum of the reciprocals of object distance and image distance is equal to the __________ of a mirror.<br>
Question 3 :
A beam of light passing from air enters into the glass. Identify which of the following statements is true?<br/>
Question 5 :
A photograph of a horse is taken by a camera whose lens has been painted with black stripes. The photograph will be of a :
Question 6 :
State whether true or false:A concave lens forms a magnified or diminished image depending on the distance of object from it.<br/>
Question 7 :
Ratio of the size of the image to the size of the object is known as:
Question 8 :
In case of a virtual and erect image, the magnification created by the mirror is
Question 9 :
If an object is placed $10\ cm$ infront of a concave mirror of focal length $20\ cm,$ the image will be
Question 12 :
A ray of light passes through a glass slab. and the angle of emergence is found smaller than the angle of incidence. So, we may conclude that the glass slab
Question 13 :
When a drop of oil is spread on a water surface, it displays beautiful colours in daylight because of :
Question 16 :
When a ray of light passes through a rectangular slab, made up of some transparent material other than glass, the emergent ray is
Question 17 :
The focal length of a combination of lenses formed with lenses having powers of $+2.50\ D$ and $-3.75\ D$ will be
Question 21 :
Why does light bends while travelling from one medium to another?<br>
Question 22 :
Two lenses one of focal length $20 cm$. (convex lens) and another of focal length $-15 cm$ (concave lens) are placed in contact. Identify the correct statement.
Question 23 :
An object is placed at a distance $2 f$ from the pole of a convex mirror of focal length $f$ . The linear magnification is:<br/>
Question 24 :
A film projector magnifies a $\displaystyle 100\ { cm }^{ 2 }$ film strip on a screen. If the linear magnification is $4$, the area of the magnified film on the screen is be $\displaystyle 1000\ { cm }^{ 2 }$
Question 25 :
Find the nature of image when an object is placed at $2f$ from the pole of a convex mirror of focal length $f$
Question 26 :
Two lenses have powers +D and -2D respectively. The power of combination is:
Question 27 :
Calculate the magnification of an object if it is kept at a distance of $3 cm$ from a concave mirror of focal length $4 cm$:
Question 29 :
A convex lens of focal length $84\ cm$ is in contact with a concave lens of focal length $12\ cm$. The power of combination (in diopters) is
Question 30 :
Assertion: Power of the lens is larger if its focal length is smaller.
Reason: Power of the lens measures the ability to converge or diverge the refracted rays.
Question 31 :
Two thin lenses of power $+3.5D, -2D$ are placed in contact. Find the power of lens combination.
