an object 4cm in size is placed at 26 cm in front of a conacave mirror of focal length 15cm at what distance from the mirror would a screen be placed in order to obatain in sharp image? find the nature and the size of the image
Answers
Answered by
11
Given
- Object Size = 4 cm
- Object Distance = -26 cm
- Mirror used = Concave
- Focal length = -15 cm
To Find
- Nature and size of the image
Solution
● Mirror Formula :- 1/v + 1/u = 1/f
● Magnification :- Hᵢ/Hₒ = -v/u
✭ Image Distance :
→ 1/v + 1/u = 1/f
→ 1/v + 1/-26 = 1/-15
→ 1/v - 1/26 = -1/15
→ 1/v = 1/26 - 1/15
→ 1/v = 15/390 - 26/390
→ 1/v = (15-26)/390
→ 1/v = 11/390
→ v = 390/11
→ v = 35.45 cm
✭ Size of the Image :
→ Hᵢ/Hₒ = -v/u
→ Hᵢ/4 = -(-35.45)/-25
→ Hᵢ = 35.45/25 × 4
→ Hᵢ = 5.672 cm
∴ The image is real, inverted placed at 35.45 cm and magnified
Similar questions