Light

1.Why does a fish lying under water appear to be raised slightly above its actual depth?
 
A. Due to diffraction of light
 
B. Due to refraction of light
 
C. Due to polarization of light
 
D. Due to reflection of light
 
Option “B” is correct.
The apparent depth is caused due to the refraction of light as the light rays travel from one medium to another.
2.Due to which the person present inside the water appears to be at a higher height than its actual position above the surface of the water.
 
A. due to refraction of light
 
B. due to reflection of light
 
C. because of the personification of light
 
D. due to diffraction of light
 
Option “A” is correct.
An object seen in the water will usually appear to be at a different depth than it actually is, due to the refraction of light rays as they travel from the water into the air.
3.A stick immersed in water appears to be bent due to which phenomenon?
 
A. reflection of light
 
B. diffraction of light
 
C. Refraction of light
 
D. scattering of light
 
Option “C” is correct.
This phenomenon occurs due to the property of light called refraction of light. When a stick is immersed in water, in actually we are putting it from rarer medium to denser medium. So, when the rays of light pass from a rarer medium to the denser medium they move towards the normal, the part of stick immersed in water appears to bend when immersed in water and this refraction causes an apparent shift in the position of the part of the rod within the water.
4.When a ray of light passes from a rarer medium to a denser medium, it
 
A. goes straight
 
B. towards to the normal
 
C. moves away from normal
 
D. none of these
 
Option “B” is correct.
When a light ray travels from a rarer medium to a denser medium, the speed of light reduces, and it bends towards the normal.
5.Total internal reflection occurs when light is
 
A. from a rarer medium to a denser medium with an angle of incidence greater than the critical angle
 
B. from a denser medium to a rarer medium angle of incidence greater than critical angle.
 
C. from rarer medium to denser medium
 
D. from denser medium to rarer medium
 
Option”B” is correct.
When light travels from denser to rarer medium, it bends away from the normal. When the angle of incidence becomes greater than the critical angle (angle of incidence for which angle of refraction is 90), light gets reflected in the same medium without undergoing refraction and this phenomenon is known as total internal reflection.
6.What causes a rainbow to form?
 
A. refraction and dispersion
 
B. scattering and refraction
 
C. diffraction and refraction
 
D. refraction, internal reflection, and dispersion
 
Option “D” is correct.
Rainbow can be seen in the sky opposite to the sun just after the rainfall when the water droplets are suspended in the air. The light rays from the sun enter the water droplet and undergo refraction at the surface, then it hits the other end of a droplet and gets internally reflected showing dispersion into seven colors.Hence rainbow formation is the combined phenomena of refraction, internal reflection, and dispersion
7.What is the phenomenon that creates a mirage called?
 
A. personalization
 
B. diffraction
 
C. polarization
 
D. Total internal reflection
 
Option “D” is correct.
The phenomenon which causes the formation of mirage is known as total internal reflection. When light goes from an optically denser to an optically rarer medium at an angle greater than the critical angle, TIR takes place. This causes the illusion of presence of water in deserts known as mirage.
8.Endoscopy, a technique used to explore the stomach or other inner parts of the body is based on the phenomenon of
 
A. Diffraction
 
B. Interference
 
C. Total internal reflection
 
D. Polarization
 
Option “A” is correct.
The endoscopy produces uses an endoscope to examine the interior of the hollow organ or cavity of the body by the phenomenon of total internal reflection.
9.Why does the bottom of a beaker filled with liquid appear slightly raised?
 
A. refraction
 
B. personalization
 
C. diffraction
 
D. reflection
 
Option “A” is correct.
Due to the refraction of light, the water appears higher than its actual level when seen from above. This is a phenomenon due to which a pencil appears bent too. The light entering from denser to lighter medium bends towards the normal and this causes the refraction of light and the object appears to be raised.
10.Sunlight can undergo internal reflection if it enters from :
 
A. glass to air
 
B. air to glass
 
C. air to water
 
D. water to glass
 
Option “A” is correct.