Optic Short Questions
QUESTION 1:
Which type of lens would you use to start fire from light of sun .
concave or convex ? At what distance from the lens should the paper be
held for best result?
ANSWER:
We will use a convex lens (a thin converging lens) to start fire from light
of sun . For better results the paper should be held at yhe focus (F).
Explanation:
A convex lens, converge all rays falling on it to a single point due to
which the paper burns from the heat of sun. Moreover, all the rays
focused on the focal lenght. That is why if we held a piece of paper on
the focus, it will burn soon as compared to other positions.
QUESTION 2:
If a concave mirror produces real image, is the image be necessarily
, inverted? Explain.
ANSWER:
Yes, the image be necessarily inverted if a concave mirror produces a
real image .
Explanation:
A concave mirror produces a real images when the object is placed
beyond C, On C, and between C AND F. In all these cases the image are
real and inverted . HOwever the object is placed is placed between pole
P and focus F , th eimage formed will be up right but they will be a
virtual image and not real. That is why it is said that a real image formed
by concave lens will always be inverted.
QUESTION3:
Are rear-view mirror in cars concave or convex?
ANSWER:
The raer-view mirror in cars are always convex in nature.
Explanation:
QUESTION 1:
Which type of lens would you use to start fire from light of sun .
concave or convex ? At what distance from the lens should the paper be
held for best result?
ANSWER:
We will use a convex lens (a thin converging lens) to start fire from light
of sun . For better results the paper should be held at yhe focus (F).
Explanation:
A convex lens, converge all rays falling on it to a single point due to
which the paper burns from the heat of sun. Moreover, all the rays
focused on the focal lenght. That is why if we held a piece of paper on
the focus, it will burn soon as compared to other positions.
QUESTION 2:
If a concave mirror produces real image, is the image be necessarily
, inverted? Explain.
ANSWER:
Yes, the image be necessarily inverted if a concave mirror produces a
real image .
Explanation:
A concave mirror produces a real images when the object is placed
beyond C, On C, and between C AND F. In all these cases the image are
real and inverted . HOwever the object is placed is placed between pole
P and focus F , th eimage formed will be up right but they will be a
virtual image and not real. That is why it is said that a real image formed
by concave lens will always be inverted.
QUESTION3:
Are rear-view mirror in cars concave or convex?
ANSWER:
The raer-view mirror in cars are always convex in nature.
Explanation:
