Q1: What are luminous objects?
Ans: Objects that give out or emit light of their own are known as luminous objects.
Q2: Butter paper is __________object. (transparent/translucent/opaque)
Q3: Give two examples of non-luminous objects.
Ans: Chair and shoe
Q4: What type of object is said to be transparent?
Ans: If we are able to see clearly through an object, it is said to be transparent.
Q5: Give two examples of transparent objects.
Ans: Glass and water
Glass and Water are both Transparent
Q6: Give two example of luminous object.
Ans: Sun and torch bulb
Q7: What are translucent objects?
Ans: There are some objects through which we can see but not clearly. Such objects are known as translucent objects.
Q8: Wooden piece is a ___________object. (translucent/opaque)
Q9: If we cannot see through an object at all, it is an __________object.
Q10: Give two examples of opaque objects.
Ans: Plastic box and wooden table
Q11: When are shadows formed?
Ans: Shadows are formed when an opaque object comes in path of light
Q12: The shadows can be seen only on a screen. (TRUE/FALSE)
Q13: By shadows, we may know about ___________ of object. (shape/size)
Q14: Why we should not look directly at sun?
Ans: We should not look directly at sun because that could be extremely harmful for the eyes.
Q15: Light travels along ___________path.
Q16: Mirror changes direction of light that falls on it. (TRUE/FALSE)
Mirror changes Direction of Light
Q17: We can see our face in mirror because mirror ___________our face.
Q18: Images are different from shadows. (TRUE/FALSE)
Q19: __________object makes shadows.
Q20: Stars and sun are __________source of light.
Q21: _________objects allows light to pass through them partially.
Q22: Pinhole camera produces ________image.
Q23: A sheet of polythene is ___________object. (luminous/non luminous)
Ans: Non luminous
Q24: Shadows are of two kinds. What are they?
Ans: Umbra and penumbra.
Q25: Clean water is __________. (transparent/translucent/opaque)
Q26: Shadows are not cast by every type of object. (TRUE/FALSE)
Q27: Moon is _________body. (Luminous/non-luminous)
Ans: Non luminous
Q28: Air and water are _________.
a) Transparent and non-luminous
b) Opaque and non luminous.
c) Translucent and non-luminous.
Ans: a) Transparent and non-luminous
Q29: What type of object is sheet of cellophane? (transparent/translucent/opaque)
Q30: Moon reflects ________light that falls on it.
Q31: Which of the following is not translucent?
d) Sheet of polythene
Ans: b) Notebook
Q32: ___________objects allows light to pass through them completely.