Physicsmedium · Past Paper
If a lens has a power of -2.5 D, what is its focal length?
A-40 cm
B-25 cm
C40 cm
D25 cm
✓ Correct Answer: A — -40 cm
f = 1/P = 1/(-2.5) = -0.4 m = -40 cm.
Share this question
More from Physics
- 1 km/h is equal to how many m/s?
- Which of the following speed-time graphs represents a body whose speed is decreasing linearly?
- A bus increases its speed from 36 km/h to 72 km/h in 10s. Its acceleration is:
- If a body moves with constant velocity, its acceleration is:
- What is the work done by a person in carrying a 20 kg bag on his head while walking 50 m on a horizontal road?