Physicsmedium · Past Paper
What is the power of a combination of a convex lens (f=20cm) and a concave lens (f=25cm)?
A+1 D
B-1 D
C+9 D
D-9 D
✓ Correct Answer: A — +1 D
P1 = 1/0.2 = 5D, P2 = 1/-0.25 = -4D. Total P = 5 - 4 = 1D.
Share this question
More from Physics
- Negative acceleration is also known as:
- Work done is a maximum when the angle between force and displacement is:
- A body moving with a speed of 36 km/h is moving with how many m/s?
- Which of the following does NOT affect the strength of an electromagnet?
- A balloon is at a height of 81m and is ascending with a velocity of 12 m/s. A body is dropped from it. If g=10, the body reaches ground in: