5th year homework.
Q1. Explain with the aid of a diagram how you would carryout an experiment to find the focal length of a convex lens.
Q2. An object is placed 40cm in front of a concave lens of focal length 20cm. Find the position and nature of the image.
Q3. A lens has a power of 15 m-1, find its focal length.
Q4. Two lenses of power 20 m-1 each are placed in contact. What is their combined power?
Q5. Two convex lenses are placed in contact with each other. Each lens has a focal length of 20cm. Find their combined focal length.
Q6.Two lenses one convex and the other concave are placed in contact. They have focal lengths of 20cm and 40cm respectively. Find their combined focal length.
Q7. Explain long and short sightedness.
Q8. Name and explain the function of the four main parts of the eye.