Advertisements
Advertisements
प्रश्न
Why are the mirrors fitted on the outside of cars convex?
Advertisements
उत्तर
- The image formed by a convex mirror is small and straight.
- This image remains straightforward; But as we move the mirror further away from the object, the image becomes smaller.
- As a result, we see all the surrounding images in the mirror.
- The use of convex mirrors in the outside of the vehicle gives the driver a straight, narrow and clear image of the vehicles behind the vehicle.
- Therefore, the mirror fitted on the outside of the vehicle is convex.
APPEARS IN
संबंधित प्रश्न
Analyse the following observation table showing variation of image distance (v) with object distance (u) in case of a convex lens and answer the questions that follow, without doing any calculations:
| S. No. | Object distance u(cm) | Image distance v(cm) |
| 1 | −90 | +18 |
| 2 | −60 | +20 |
| 3 | −30 | +30 |
| 4 | −20 | +60 |
| 5 | −18 | +90 |
| 6 | −10 | +100 |
(a) What is the focal length of the convex lens? Give reason in support of your answer.
(b) Write the serial number of that observation which is not correct. How did you arrive at this conclusion?
(c) Take an appropriate scale to draw ray diagram for the observation at S. No. 4 and find the approximate value of magnification.
A student obtains a blurred image of a distant object on a screen using a convex lens. To obtain a distinct image on the screen he should move the lens
(A) away from the screen
(B) towards the screen
(C) to a position very far away from the screen
(D) either towards or away from the screen depending upon the position of the object
Find the nature and focal length of a spherical mirror whose radius of curvature is +24 cm.
Explain with a suitable diagram, how a concave mirror converges a parallel beam of light rays. Mark clearly the pole, focus and centre of curvature of concave mirror in this diagram.
A mirror forms an image which is 30 cm from an object and twice its height.
(a) Where must the mirror be situated?
(b) What is the radius of curvature?
(c) Is the mirror convex or concave?
An object is placed at a long distance in front of a convex mirror of radius of curvature 30 cm. State the position of its image.
What type of mirror should be used as a shop security mirror?
What would your image look like if you stood close to a large:
convex mirror?
An arrow 2.5 cm high is placed at a distance of 25 cm from a diverging mirror of focal length 20 cm. Find the nature, position and size of the image formed.
The radius of curvature of a convex mirror used as a rear view mirror in a moving car is 12.0 m. A truck is coming from behind it at a distance of 3.54 m. Calculate (a)
- position and
- size of the image relative to the size of the truck.
- What will be the nature of the image?
Draw ray diagrams to represent the nature, position and relative size of the image formed by a convex lens for the object placed:
at 2F1,
What is the effect on the size and position of the image of moving the object (i) towards the lens, and (ii) away from the lens?
The magnification produced by a spherical mirror and a spherical lens is + 0.8.
(a) The mirror and lens are both convex
(b) The mirror and lens are both concave
(c) The mirror is concave but the lens is convex
(d) The mirror is convex but the lens is concave
The focal length of a convex mirror is equal to its radius of curvature.
To determine the focal length of a convex lens by obtaining a sharp image of a distant object we generally follow the following steps which are not in proper sequence.
(a) Hold the lens between the object and the screen
(B) Measure the distance between the lens and the screen
(C) Select a well lit distant object
(D) Place a screen opposite to the object on the lab table
(e) Adjust the position of the lens to form a sharp image
The correct sequence of these steps is:
(A) c, a, d, e, b
(B) c, d, a, e, b
(C) c, d, e, a, b
(D) c, a, e, d, b
List four properties of the image formed by a convex mirror when object is placed between focus and pole of the mirror.
Assertion: Convex mirrors are used as a rearview mirror in vehicles for observing traffic at our back.
Reason: A convex mirror has a much larger field of view.
Assertion: A real image cannot be produced by plane or convex mirror.
Reason: The focal length of a convex mirror is always taken as positive.
Which type of mirror is used in the following?
Street lights
