The inside portion of part of a hollow metal sphere of diameter 20cm is polished. The portion will therefore form a
concave mirror of focal length 5cm
concave mirror of focal length 10cm
convex mirror of focal length 5cm
convex mirror of focal length 20cm
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Discussions (60)
Recall that Focal length (F)= Radius of curvature(R)/2
But, Radius(R)=Diameter (D)/2 ;: R=20/2 ; R=10cm.
Therefore, Focal length (F)= 10/2 ;: F=5cm.
A convex mirror is that mirror that is coated or polished on the inside.
Therefore, The answer is Convex mirror of focal length 5cm
A concave mirror is silvered coated at the back while the inside is d reflecting surface while a convex mirror is silvered coated inside why the outside is d reflecting surface. But note Dat a polish surface is a good reflector of light rays thereby functioning as a reflecting surface as in concave mirror. Dats y concave is d answer
Recall that Focal length (F)= Radius of curvature(R)/2
But, Radius(R)=Diameter (D)/2 ;: R=20/2 ; R=10cm.
Therefore, Focal length (F)= 10/2 ;: F=5cm.
A convex mirror is that mirror that is coated or polished on the inside.
Therefore, The answer is Convex mirror of focal length 5cm (c)
radius=d/2=10cm. also focal length is r/2=5cm.and we know concave mirror is curved inwards (the inside is painted)so A is correct.
the answer should be a convex mirror because it inside surface is polish and the focal length is 5cm where f=d/4
The inner surface is polished, the outer surface is the reflecting surface hence a convex mirror...f = d/4 = 5 cm...𝐂
Some people are jst guessing and others wil look rather look at their text books and some wil follow other people's anwers.please undstand d question frst and try to gv an answer b4 looking at d options bcos if u dnt undstand d question u definitly guess it there are some people dat gv d correct ansa abv whch is A.
