Advertisements
Advertisements
Question
If the radius of curvature of a concave mirror is 20 cm, its focal length is:
Options
10 cm
20 cm
40 cm
80 cm
Advertisements
Solution
10 cm
APPEARS IN
RELATED QUESTIONS
Draw ray diagrams to show the principal focus of a concave mirror.
A student obtained a sharp image of a candle flame placed at the distant end of the laboratory table on a screen using a concave mirror to determine its focal length. The teacher suggested him to focus a distant building, about 1 km away from the laboratory, for getting more correct value of the focal length. In order to focus the distant building on the same screen, the student should slightly move the
(a) mirror away from the screen
(b) screen away from the mirror
(c) screen towards the mirror
(d) screen towards the building
Name the mirror that can give an erect and enlarged image of an object.
An object is placed at the following distances from a concave mirror of focal length 15 cm, turn by turn:
(a) 35 cm
(b) 30 cm
(c) 20 cm
(d) 10 cm
Which position of the object will produce:
(i) a magnified real image?
(ii) a magnified virtual image?
(iii) a diminished real image?
(iv) an image of same size as the object?
What kind of mirror can have a focal length of, −20 cm?
A concave mirror produces three times enlarged virtual image of an object placed at 10 cm in front of it. Calculate the radius of curvature of the mirror.
How can a concave mirror be used to obtain a virtual image of an object? Draw a diagram to illustrate your answer.
An object at a distance of 30 cm from a
concave mirror gets its image at the same point. The focal length of the mirror is ______.
You are provided with a concave mirror, a convex mirror, a concave lens and a convex lens. To obtain an enlarged image of an object you can use either
The image formed by a concave mirror is real, inverted and of the same size as that of the object, the position of the object should be ______.
