Q15.Car B overtakes another car A at a relative speed of 40 m s−1 . How fast will the image of car B appear to move in the mirror of focal length 10 cm fitted in car A , when the car B is 1. 9 m away from the car A ? (1) 0. 1 m s−1 (2) 0. 2 m s−1 (3) 40 m s−1 (4) 4 m s−1
What This Question Tests
This problem combines the mirror formula with the concept of relative velocity in reflection to calculate the apparent speed of an image in a rearview mirror, requiring careful sign conventions.
Concepts Tested
Formulas Used
1/f = 1/v + 1/u
m = -v/u
v_image = - (v/u)² v_object
📚 NCERT Sections This Tests
9.15 — Apply Mirror Equation And The Condition:
Physics Class 12 · Chapter 9
9.15 Apply mirror equation and the condition: (a) f < 0 (concave mirror); u < 0 (object on left) (b) f > 0; u < 0 (c) f > 0 (convex mirror) and u < 0 (d) f < 0 (concave mirror); f < u < 0 to deduce the desired result.
9.2 — A 4.5 Cm Needle Is Placed 12 Cm Away From A Convex Mirror Of Focal
Physics Class 12 · Chapter 9
9.2 A 4.5 cm needle is placed 12 cm away from a convex mirror of focal length 15 cm. Give the location of the image and the magnification. Describe what happens as the needle is moved farther from the mirror.
9.1 — A Small Candle, 2.5 Cm In Size Is Placed At 27 Cm In Front Of A Concave
Physics Class 12 · Chapter 9
9.1 A small candle, 2.5 cm in size is placed at 27 cm in front of a concave mirror of radius of curvature 36 cm. At what distance from the mirror should a screen be placed in order to obtain a sharp image? Describe the nature and size of the image. If the candle is moved closer to the mirror, how would the screen have to be moved?
📋 Question Details
- Chapter
- Ray Optics
- Topic
- Spherical Mirrors
- Year
- 2021
- Shift
- 26 Aug Shift 1
- Q Number
- Q15
- Type
- Multi concept
- NCERT Ref
- Class 12 Physics Ch 9: Ray Optics and Optical Instruments
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