Question 1 :
A concave mirror forms the real image of an object which is magnified 4 times. The objects is moved 3 cm away, the magnification of the image is 3 times. What is the focal length of the mirror?
Question 2 :
Assertion: Light waves have different refractive indices in different media.
Reason: Variations in the velocities of light in different media cause the refractive indices to be different.
Question 3 :
A sound wave is travelling in a medium in which the velocity is $$v$$. It is incident in the second medium in which the velocity of the wave is $$2v$$. What should be the minimum angle of incidence in the first medium, so that the wave fails to cross the surface of separation of the two media?
Question 4 :
When a ray of light traveling from vacuum to a medium of refractive index $$\mu $$, the angle of incidence is twice the angle of refraction. The incident angle is :<br/>
Question 5 :
A ray of light is travelling through a medium of refractive index $$\dfrac {1}{\sqrt {2}}$$ with respect to air. When it is incident on the surface making an angle $$45^{\circ}$$ with the surface, which of the following will take place?
Question 8 :
In passing through a boundary, refraction will not take place if:
Question 9 :
A ray of light in a liquid of refractive index 1.4, approaches the boundary surface between the liquid and air at an angle of incidence whose sine is 0.8. Which of the following statements is correct about the behaviour of the light
Question 10 :
An air bubble in a glass with refractive index $$1.5$$ (near normalincidence) i.e. $$5\ cm$$ deep when viewed from one surface and $$3\ cm$$ deep when viewed from the opposite face. The thickness(in $$cm$$) of the is.
Question 11 :
A $$4.0$$-cm-high object is placed at a distance of $$60$$ cm from a concave lens of focal length $$20$$ cm. Find the size of the image.
Question 12 :
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 13 :
A thin layer of water is transparent but a very thick layer of water is
Question 14 :
The distance between an object and a divergent lens is $$m$$ times the focal length of the lens. The linear magnification produced by the lens is
Question 15 :
A ray of light falls into a medium of $$R.l.\mu$$ from vacuum. The angle of incidence is found to be twice the angle of refraction. Then, the angle of incidence is
Question 16 :
The $$X-Z$$ plane separates two media $$A$$ and $$B$$ of refractive indices $$\mu_{A}=1.5$$ and $$\mu_{B}=2.$$ A ray of light travels from $$A$$ to $$B$$, its direction in two media are given by unit vectors. $$\hat {u}_{A}=a\hat {i}+b\hat {j}$$ and $$\hat {u}_{B}=c\hat {i}+d\hat {j}$$ respectively, then :<br/>
Question 17 :
A ray of light coming parallel to the principal axis after passing through a convex lens, passes through its
Question 18 :
An object is placed at 20 cm in front of a concave mirror produces three times magnified real image. What is focal length of the concave mirror?
Question 19 :
A ray of light travelling in a transparent medium falls on a surface separating the medium from air at an angle of incidence of $$45^{o}$$. The ray undergoes total internal reflection. If $$n$$ is the refractive index of the medium with respect to air, select the possible value(s) of $$n$$ from the following:
Question 20 :
State whether true or false :A concave lens is used as a magnifying glass
Question 21 :
A convex lens of focal length 80 cm and concave lens of focal length 50 cm are combined together. What will be their resultant power?<br>
Question 22 :
A square card of side length 1 mm is being seen through a magnifying lens of focal length 10 cm. The card is placed at a distance of 9 cm from the lens. The apparent area of the card through the lens is
Question 24 :
A ray of light travelling inside a rectangular glass block of refractive index $$\sqrt2$$ is incident on the glass-air surface at an angle o incidence of $$45^o$$.The refractive index of air is one. Under these conditions the ray will
Question 25 :
A plate of thickness t made of a material of refractive index $$\mu$$ is placed in front of one of the slits in a double slit experiment. What should be the minimum thickness t which will make the intensity at the center of the fringe pattern zero?
