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20 questions
Which of the following can make a parallel beam of light when light from a point source is incident on it ?
Concave mirror as well as convex lens
Convex mirror as well as concave lens
Two plane mirrors placed at 90° to each other
Concave mirror as well as concave lens
A 10 mm long awl pin is placed vertically in front of a concave mirror. A 5 mm long image of the awl pin is formed at 30 cm in front of the mirror. The focal length of this mirror is
-30 cm
-20 cm
-40 cm
-60 cm
Under which of the following conditions a concave mirror can form an image larger than the actual object ?
When the object is kept at a distance equal to its radius of curvature
When object is kept at a distance less than its focal length
When object is placed between the focus and centre of curvature
When object is kept at a distance greater than its radius of curvature
The diagrams showing the correct path of the ray after passing through the
II and III only
I and II only
I, II and III
I, II and IV
A light ray enters from medium A to medium B as shown in figure. The refractive index of medium B relative to A will be
greater than unity
less than unity
equal to unity
zero
Beams of light are incident through the holes A and B and emerge out of box through the holes C and D respectively as shown in the figure. Which of the following could be inside the box ?
A rectangular glass slab
A convex lens
A concave lens
A prism
A beam of light is incident through the holes on side A and emerges out of the holes on the other face of the box as show in the figure. Which of the following could be inside the box ?
Concave lens
Rectangular glass slab
Prism
Convex lens
Which of the following statements is true ?
A convex lens has 4 dioptre power having a focal length 0.25 m
A convex lens has -4 dioptre power having a focal length 0.25 m
A concave lens has 4 dioptre power having a focal length 0.25 m
A concave lens has -4 dioptre power having a focal length 0.25 m.
Magnification produced by a rear view mirror fitted in vehicles
is less than one
is more than one
is equal to one
can be more than or less than one depending upon the position of the object in front of it.
Rays from Sun converge at a point 15 cm in front of a concave mirror. Where should an object be placed so that size of its image is equal to the size of the object ?
15 cm in front of the mirror
30 cm in front of the mirror
between 15 cm and and 30 cm in front of the mirror
more than 30 cm in front of the mirror
A student used a device (X) to obtain/focus the image of a well illuminated distant building on a screen (S) as shown alongside in the diagram. Select the correct statement about the device (X).
This device is a concave lens of focal length 8 cm.
This device is a convex mirror of focal length 8 cm.
This device is a convex lens of focal length 4 cm.
This device is a convex lens of focal length 8 cm.
A student obtains a sharp image of the distant window (W) of the school laboratory on the screen (S) using the given concave mirror (M) to determine its focal length. Which of the following distances should he measure to get the focal length of the mirror ?
MW
MS
SW
MW-WS
The deviation of light ray from its path when it travels from one transparent medium to another transparent medium is called
reflection
refraction
dispersion
scattering
When light falls on a surface and bounces back to the medium, the phenomena is called
When rays of light after reflection meet a point ………….. image is formed.
……………. is ratio of height of image to height of object.
Assertion: Incident light is reflected in only one direction from a smooth surface.
Reason: Since the angle of incidence and the angle of reflection are same, a beam of parallel rays of light falling on a smooth surface is reflected as a beam of parallel light rays in one direction only.
Both the Assertion and the Reason are correct and the Reason is the correct explanation of the Assertion.
The Assertion and the Reason are correct but the Reason is not the correct explanation of the Assertion.
Assertion is true but the Reason is false.
The statement of the Assertion is false but the Reason is true.
Assertion: Pupil is black in color.
Reason: Pupil is black in color as no light is reflected in it.
Both the Assertion and the Reason are correct and the Reason is the correct explanation of the Assertion.
The Assertion and the Reason are correct but the Reason is not the correct explanation of the Assertion.
Assertion is true but the Reason is false.
The statement of the Assertion is false but the Reason is true.
A person standing in front of a mirror finds his image larger than himself. This shows that mirror is convex in nature.
True
False
A convex and a concave lens of equal focal length behaves as a regular glass slab receiving light normally.
True
False
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