Light Test

Result

Light Test - 18

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Weekly Quiz Competition

Question 1
1 / -0

How many mirrors are used in a periscope?

A
1

B
2

C
3

D
4

Solution

A periscope is defined as an instrument used for observing over, around, or through an obstacle or object which is prevented by a direct line of sight. Periscopes are fitted with two plane mirrors at the ends of the tube at an angle of $$45^0$$ with the side of the tube.
Question 2
1 / -0

Which of the following instrument is used for observing people/things without letting the people know of it.

A
Kaleidoscope

B
Periscope

C
Bioscope

D
Magnoscope

Solution

Periscope may be used for observing people/things without letting the people know of it. Reflection from the two mirrors enables us to see objects which are not visible directly.
Question 3
1 / -0

In a periscope, plane mirrors are fixed at the bends of the tube at an angle of _________ with the side of the tube.

A
$$\displaystyle { 30 }^{ o }$$

B
$$\displaystyle { 90 }^{ o }$$

C
$$\displaystyle { 45 }^{ o }$$

D
$$\displaystyle { 60 }^{ o }$$

Solution

In a periscope two plane mirrors are fixed at the bends of the tube at an angle of $$\displaystyle { 45 }^{ o }$$ with the side of the tube.The inner side of the tube is blackened to avoid any unwanted reflection of light.
Question 4
1 / -0

Periscope is used for:

A
observation beyond the obstruction

B
watching TV more clearly

C
viewing nearby objects by persons suffering from visual deformities

D
all of these

Solution

Periscope, which works on the principle of reflection of light, is used to make observation beyond obstruction in the direct line of sight.
Question 5
1 / -0

Which of the following is not the proper use of a periscope?

A
A periscope is used by scientists to see planetary bodies which are not seen by telescopes

B
A periscope is used in submarines to see objects on the surface of water

C
A periscope is used by soldiers, present in trench, to observe the movement of the enemy

D
A periscope is used to observe football match beyond the boundary wall of a playground

Solution

Images seen through periscopes are not magnified. So, cannot be used to observe the planetary bodies.
Periscope, optical instrument used in land and sea warfare, submarine navigation, and elsewhere to enable an observer to see his surroundings while remaining undercover, behind armor, or submerged.
Question 6
1 / -0

Periscope is fitted with:

A
glass slabs

B
convex mirrors

C
transparent plastic sheets

D
plane mirrors

Solution

Periscope is a device that uses the property of reflection of light to show the object at difficult angles of vision, these are mostly used in submarines. Periscopes are fitted with two plane mirrors at the ends of the tube at an angle of $$45^0$$ with the side of the tube.
Question 7
1 / -0

Inner side of the cylindrical tube of a periscope is blackened to avoid:

A
unwanted refraction

B
unwanted reflection

C
diffusion

D
both a and b

Solution

The inner side of the cylindrical tube of a periscope is blackened to avoid any unwanted reflection of light. The reflected lights which are falling on the black surface get absorbed.
Question 8
1 / -0

The mirror used in periscope is:

A
convex mirror

B
concave mirror

C
plane mirror

D
any of the above can be used

Solution

Plane mirrors are used in a reflecting periscope.Two plane mirrors are fixed at the bends of the tube at an angle of $$45^{ o }$$ with the side of the tube.
Question 9
1 / -0

Colourful patterns are formed in a kaleidoscope by:

A
refraction

B
reflection

C
dispersion

D
scattering

Solution

A kaleidoscope is made of three plane mirrors. When light rays enter into the structure of a kaleidoscope, they suffer multiple reflections by those plane mirrors. These multiple reflections will create some beautiful patterns.
Question 10
1 / -0

Kaleidoscope works on the principle of:

A
reflection of light from spherical mirrors

B
multiple refraction of light from spherical mirrors

C
multiple reflection of light from plane mirrors

D
reflection of light from plane mirrors

Solution

Kaleidoscope works on the principle of multiple reflection of light from plane mirrors.